SUMMARY

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 ransomware IOCs and TTPs associated with the Snatch ransomware variant identified through FBI investigations as recently as June 1, 2023.

Since mid-2021, Snatch threat actors have consistently evolved their tactics to take advantage of current trends in the cybercriminal space and leveraged successes of other ransomware variants’ operations. Snatch threat actors have targeted a wide range of critical infrastructure sectors including the Defense Industrial Base (DIB), Food and Agriculture, and Information Technology sectors. Snatch threat actors conduct ransomware operations involving data exfiltration and double extortion. After data exfiltration often involving direct communications with victims demanding ransom, Snatch threat actors may threaten victims with double extortion, where the victims’ data will be posted on Snatch’s extortion blog if the ransom goes unpaid.

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:

For a downloadable copy of IOCs, see:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 13. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

First appearing in 2018, Snatch operates a ransomware-as-a-service (RaaS) model and claimed their first U.S.-based victim in 2019. Originally, the group was referred to as Team Truniger, based on the nickname of a key group member, Truniger, who previously operated as a GandCrab affiliate. Snatch threat actors use a customized ransomware variant notable for rebooting devices into Safe Mode [T1562.009], enabling the ransomware to circumvent detection by antivirus or endpoint protection, and then encrypting files when few services are running.

Snatch threat actors have been observed purchasing previously stolen data from other ransomware variants in an attempt to further exploit victims into paying a ransom to avoid having their data released on Snatch’s extortion blog. Note: Since November 2021, an extortion site operating under the name Snatch served as a clearinghouse for data exfiltrated or stolen from victim companies on Clearnet and TOR hosted by a bulletproof hosting service. In August 2023, individuals claiming to be associated with the blog gave a media interview claiming the blog was not associated with Snatch ransomware and “none of our targets has been attacked by Ransomware Snatch…”, despite multiple confirmed Snatch victims’ data appearing on the blog alongside victims associated with other ransomware groups, notably Nokoyawa and Conti.[1]

Initial Access and Persistence

Snatch threat actors employ several different methods to gain access to and maintain persistence on a victim’s network. Snatch affiliates primarily rely on exploiting weaknesses in Remote Desktop Protocol (RDP) [T1133] for brute-forcing and gaining administrator credentials to victims’ networks [T1110.001]. In some instances, Snatch affiliates have sought out compromised credentials from criminal forums/marketplaces [T1078].

Snatch threat actors gain persistence on a victim’s network by compromising an administrator account [T1078.002] and establishing connections over port 443 [T1071.001] to a command and control (C2) server located on a Russian bulletproof hosting service [T1583.003]. Per IP traffic from event logs provided by recent victims, Snatch threat actors initiated RDP connections from a Russian bulletproof hosting service and through other virtual private network (VPN) services [T1133].

Data Discovery and Lateral Movement

Snatch threat actors were observed using different TTPs to discover data, move laterally, and search for data to exfiltrate. Snatch threat actors use sc.exe to configure, query, stop, start, delete, and add system services using the Windows Command line. In addition to sc.exe, Snatch threat actors also use tools such as Metasploit and Cobalt Strike [S0154].

Prior to deploying the ransomware, Snatch threat actors were observed spending up to three months on a victim’s system. Within this timeframe, Snatch threat actors exploited the victim’s network [T1590], moving laterally across the victim’s network with RDP [T1021.001] for the largest possible deployment of ransomware and searching for files and folders [T1005] for data exfiltration [TA0010] followed by file encryption [T1486].

Defense Evasion and Execution

During the early stages of ransomware deployment, Snatch threat actors attempt to disable antivirus software [T1562.001] and run an executable as a file named safe.exe or some variation thereof. In recent victims, the ransomware executable’s name consisted of a string of hexadecimal characters which match the SHA-256 hash of the file in an effort to defeat rule-based detection [T1036]. Upon initiation, the Snatch ransomware payload queries and modifies registry keys [T1012][T1112], uses various native Windows tools to enumerate the system [T1569.002], finds processes [T1057], and creates benign processes to execute Windows batch (.bat) files [T1059.003]. In some instances, the program attempts to remove all the volume shadow copies from a system [T1490]. After the execution of the batch files, the executable removes the batch files from the victim’s filesystem [T1070.004].

The Snatch ransomware executable appends a series of hexadecimal characters to each file and folder name it encrypts—unique to each infection—and leaves behind a text file titled HOW TO RESTORE YOUR FILES.TXT in each folder. Snatch threat actors communicate with their victims through email and the Tox communication platform based on identifiers left in ransom notes or through their extortion blog. Since November 2021, some victims reported receiving a spoofed call from an unknown female who claimed association with Snatch and directed them to the group’s extortion site. In some instances, Snatch victims had a different ransomware variant deployed on their systems, but received a ransom note from Snatch threat actors. As a result, the victims’ data is posted on the ransomware blog involving the different ransomware variant and on the Snatch threat actors’ extortion blog.

Indicators of Compromise (IOCs)

The Snatch IOCs detailed in this section were obtained through FBI investigations from September 2022 through June 2023.

Email Domains and Addresses

Since 2019, Snatch threat actors have used numerous email addresses to email victims. Email addresses used by Snatch threat actors are random but usually originate from one of the following domains listed in Tables 1 and 2:

Table 1: Malicious Email Domains Observed in Use by Snatch Threat Actors

Email Domains
sezname[.]cz
cock[.]li
airmail[.]cc

Table 2 shows a list of legitimate email domains offering encrypted email services that have been used by Snatch threat actors. These email domains are all publicly available and legal. The use of these email domains by a threat actor should not be attributed to the email domains, absent specific articulable facts tending to show they are used at the direction or under the control of a threat actor.

Table 2: Legitimate Email Domains Observed in Use by Snatch Threat Actors

Email Domains
tutanota[.]com / tutamail[.]com / tuta[.]io
mail[.]fr
keemail[.]me
protonmail[.]com / proton[.]me
swisscows[.]email

The email addresses listed in Table 3 were reported by recent victims.

Table 3: Snatch’s Email Addresses Reported by Recent Victims

Email Addresses
sn.tchnews.top@protonmail[.]me
funny385@swisscows[.]email
funny385@proton[.]me
russellrspeck@seznam[.]cz
russellrspeck@protonmail[.]com
Mailz13MoraleS@proton[.]me
datasto100@tutanota[.]com
snatch.vip@protonmail[.]com

TOX Messaging IDs

TOX Messaging IDs
CAB3D74D1DADE95B52928E4D9DFC003FF5ADB2E082F59377D049A91952E8BB3B419DB2FA9D3F
7229828E766B9058D329B2B4BC0EDDD11612CBCCFA4811532CABC76ACF703074E0D1501F8418
83E6E3CFEC0E4C8E7F7B6E01F6E86CF70AE8D4E75A59126A2C52FE9F568B4072CA78EF2B3C97
0FF26770BFAEAD95194506E6970CC1C395B04159038D785DE316F05CE6DE67324C6038727A58 NOTE: According to ransom notes, this is a “Customer service” TOX to reach out to if the original TOX ID does not respond.

Folder Creation

Folder Creation
C:$SysReset

Filenames with Associated SHA-256 Hashes

Filenames	SHA-256
qesbdksdvnotrjnexutx.bat	0965cb8ee38adedd9ba06bdad9220a35890c2df0e4c78d0559cd6da653bf740f
eqbglqcngblqnl.bat	1fbdb97893d09d59575c3ef95df3c929fe6b6ddf1b273283e4efadf94cdc802d
safe.exe	5950b4e27554585123d7fca44e83169375c6001201e3bf26e57d079437e70bcd
safe.exe	7018240d67fd11847c7f9737eaaae45794b37a5c27ffd02beaacaf6ae13352b3
safe.exe	28e82f28d0b9eb6a53d22983e21a9505ada925ebb61382fabebd76b8c4acff7c
safe.exe	fc31043b5f079ce88385883668eeebba76a62f77954a960fb03bf46f47dbb066
DefenderControl.exe	a201f7f81277e28c0bdd680427b979aee70e42e8a98c67f11e7c83d02f8fe7ae
PRETTYOCEANApplicationdrs.bi	6992aaad3c47b938309fc1e6f37179eb51f028536f8afc02e4986312e29220c0
Setup.exe	510e9fa38a08d446189c34fe6125295f410b36f00aceb65e7b4508e9d7c4e1d1
WRSA.exe	ed0fd61bf82660a69f5bfe0e66457cfe56d66dd2b310e9e97657c37779aef65d
ghnhfglwaplf.bat	2155a029a024a2ffa4eff9108ac15c7db527ca1c8f89ccfd94cc3a70b77cfc57
nllraq.bat	251427c578eaa814f07037fbe6e388b3bc86ed3800d7887c9d24e7b94176e30d
ygariiwfenmqteiwcr.bat	3295f5029f9c9549a584fa13bc6c25520b4ff9a4b2feb1d9e935cc9e4e0f0924
bsfyqgqeauegwyfvtp.bat	6c9d8c577dddf9cc480f330617e263a6ee4461651b4dec1f7215bda77df911e7
rgibdcghzwpk.bat	84e1476c6b21531de62bbac67e52ab2ac14aa7a30f504ecf33e6b62aa33d1fe5
pxyicmajjlqrtgcnhi.bat	a80c7fe1f88cf24ad4c55910a9f2189f1eedad25d7d0fd53dbfe6bdd68912a84
evhgpp.bat	b998a8c15cc19c8c31c89b30f692a40b14d7a6c09233eb976c07f19a84eccb40
eqbglqcngblqnl.bat	1fbdb97893d09d59575c3ef95df3c929fe6b6ddf1b273283e4efadf94cdc802d
qesbdksdvnotrjnexutx.bat	0965cb8ee38adedd9ba06bdad9220a35890c2df0e4c78d0559cd6da653bf740f
HOW TO RESTORE YOUR FILES.TXT

Filenames with Associated SHA-1 Hashes

Filenames	SHA-1
safe.exe	c8a0060290715f266c89a21480fed08133ea2614

Commands Used by Snatch Threat Actors

Commands
wmiadap.exe /F /T /R
%windir%System32svchost.eve –k WerSvcGroup
conhost.exe 0xFFFFFFFF -ForceV1
vssadmin delete shadows /all /quiet
bcdedit.exe /set {current} safeboot minimal
REG ADD HKLMSYSTEMCurrentControlSetControlSafeBootMinimalVSS /VE /T REG_SZ /F /D Service
REG ADD HKLMSYSTEMCurrentControlSetControlSafeBootMinimalmXoRpcSsx /VE /T REG_SZ /F /D Service
REG QUERY HKLMSYSTEMCurrentControlSetControl /v SystemStartOptions
%CONHOST% “1088015358-1778111623-1306428145949291561678876491840500802412316031-33820320
“C:Program Files (x86)MicrosoftEdgeApplicationmsedge.exe” –flag-switches-begin –flag-switches-end –no-startup-window /prefetch:5
cmd /d /c cmd /d /c cmd /d /c start ” ” C:Usersgrade1AppDataLocalPRETTYOCEANluvApplicationPRETTYOCEANApplicationidf.bi.

Registry Keys

Registry Keys
HKLMSOFTWAREMicrosoftWindows Media Player NSS3.0ServersD8B548F0-E306-4B2B-BD82-25DAC3208786FriendlyName
HKUS-1-5-21-4270068108-2931534202-3907561125-1001SoftwareMicrosoftWindowsCurrentVersionShell ExtensionsCached{ED50FC29-B964- 48A9-AFB3-15EBB9B97F36} {ADD8BA80-002B-11D0-8F0F-00C04FD7D062} 0xFFFF

System Log Changes

Source	Message
TerminalServices-RemoteConnectionManager	Remote session from client name exceeded the maximum allowed failed logon attempts. The session was forcibly terminated.
Microsoft-Windows-Windows Firewall With Advanced Security%4Firewall	A rule was added (Event 2004) or modified (Event 2005) in the Windows Defender Firewall exception list. All rules included action “Allow” and rule name included “File and Printer Sharing”
Microsoft-Windows-Windows Firewall With Advanced Security%4Firewall	A Windows Defender Firewall setting was changed in private, public, and domain profile with type “Enable Windows Defender Firewall” and value of “no”.
Microsoft-Windows-TaskScheduler%4Operational	Instance of process C:Windowssvchost.exe. (Incorrect file location, should be C:WindowsSystem32svchost.exe)

Mutexes Created

Mutexes Created
Sessions1BaseNamedObjectsgcc-shmem-tdm2-fc_key
Sessions1BaseNamedObjectsgcc-shmem-tdm2-sjlj_once
Sessions1BaseNamedObjectsgcc-shmem-tdm2-use_fc_key
gcc-shmem-tdm2-fc_key
gcc-hmem-tdm2-sjlj_once
gcc-shmem-tdm2-use_fc_key

MITRE ATT&CK TACTICS AND TECHNIQUES

See Tables 4-16 for all referenced threat actor tactics and techniques in this advisory.

Table 4: Snatch Threat Actors ATT&CK Techniques for Enterprise – Reconnaissance

Technique Title	ID	Use
Gather Victim Network Information	T1590	Snatch threat actors may gather information about the victim’s networks that can be used during targeting.

Table 5: Snatch Threat Actors ATT&CK Techniques for Enterprise – Resource Development

Technique Title	ID	Use
Acquire Infrastructure: Virtual Private Server	T1583.003	Snatch threat actors may rent Virtual Private Servers (VPSs) that can be used during targeting. Snatch threat actors acquire infrastructure from VPS service providers that are known for renting VPSs with minimal registration information, allowing for more anonymous acquisitions of infrastructure.

Table 6: Snatch Threat Actors ATT&CK Techniques for Enterprise – Initial Access

Technique Title	ID	Use
Valid Accounts	T1078	Snatch threat actors use compromised user credentials from criminal forums/marketplaces to gain access and maintain persistence on a victim’s network.
External Remote Services	T1133	Snatch threat actors exploit weaknesses in RDP to perform brute forcing and gain administrator credentials for a victim’s network. Snatch threat actors use VPN services to connect to a victim’s network.

Table 7: Snatch Threat Actors ATT&CK Techniques for Enterprise – Execution

Technique Title	ID	Use
Command and Scripting Interpreter: Windows Command Shell	T1059.003	Snatch threat actors may use batch files (.bat) during ransomware execution and data discovery.
System Services: Service Execution	T1569.002	Snatch threat actors may leverage various Windows tools to enumerate systems on the victim’s network. Snatch ransomware used sc.exe.

Table 8: Snatch Threat Actors ATT&CK Techniques for Enterprise – Persistence

Technique Title	ID	Use
Valid Accounts: Domain Accounts	T1078.002	Snatch threat actors compromise domain accounts to maintain persistence on a victim’s network.

Table 9: Snatch Threat Actors ATT&CK Techniques for Enterprise – Defense Evasion

Technique Title	ID	Use
Masquerading	T1036	Snatch threat actors have the ransomware executable match the SHA-256 hash of a legitimate file to avoid rule-based detection.
Indicator Removal: File Deletion	T1070.004	Snatch threat actors delete batch files from a victim’s filesystem once execution is complete.
Modify Registry	T1112	Snatch threat actors modify Windows Registry keys to aid in persistence and execution.
Impair Defenses: Disable or Modify Tools	T1562.001	Snatch threat actors have attempted to disable a system’s antivirus program to enable persistence and ransomware execution.
Impair Defenses: Safe Mode Boot	T1562.009	Snatch threat actors abuse Windows Safe Mode to circumvent detection by antivirus or endpoint protection and encrypt files when few services are running.

Table 10: Snatch Threat Actors ATT&CK Techniques for Enterprise – Credential Access

Technique Title	ID	Use
Brute Force: Password Guessing	T1110.001	Snatch threat actors use brute force to obtain administrator credentials for a victim’s network.

Table 11: Snatch Threat Actors ATT&CK Techniques for Enterprise – Discovery

Technique Title	ID	Use
Query Registry	T1012	Snatch threat actors may interact with the Windows Registry to gather information about the system, configuration, and installed software.
Process Discovery	T1057	Snatch threat actors search for information about running processes on a system.

Table 12: Snatch Threat Actors ATT&CK Techniques for Enterprise – Lateral Movement

Technique Title	ID	Use
Remote Services: Remote Desktop Protocol	T1021.001	Snatch threat actors may use Valid Accounts to log into a computer using the Remote Desktop Protocol.

Table 13: Snatch Threat Actors ATT&CK Techniques for Enterprise – Collection

Technique Title	ID	Use
Data from Local System	T1005	Snatch threat actors search systems to find files and folders of interest prior to exfiltration.

Table 14: Snatch Threat Actors ATT&CK Techniques for Enterprise – Command and Control

Technique Title	ID	Use
Application Layer Protocols: Web Protocols	T1071.001	Snatch threat actors establish connections over port 443 to blend C2 traffic in with other web traffic.

Table 15: Snatch Threat Actors ATT&CK Techniques for Enterprise – Exfiltration

Technique Title	ID	Use
Exfiltration	TA0010	Snatch threat actors use exfiltration techniques to steal data from a victim’s network.

Table 16: Snatch Threat Actors ATT&CK Techniques for Enterprise – Impact

Technique Title	ID	Use
Data Encrypted for Impact	T1486	Snatch threat actors encrypt data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.
Inhibit System Recovery	T1490	Snatch threat actors delete all volume shadow copies from a victim’s filesystem to inhibit system recovery.

MITIGATIONS

These mitigations apply to all stakeholders. The authoring agencies recommend that software manufactures incorporate secure-by-design and -default principles and tactics into their software development practices for hardening software against ransomware attacks (e.g., to prevent threat actors from using Safe Mode to evade detection and file encryption), thus strengthening the secure posture for their customers. For more information on secure by design, see CISA’s Secure by Design and Default webpage and joint guide.

The FBI and CISA recommend organizations implement the mitigations below to improve your organization’s cybersecurity posture on the basis of the Snatch threat actor’s activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

• Reduce threat of malicious actors using remote access tools by:
  • Auditing remote access tools on your network to identify currently used and/or authorized software.
  • Reviewing logs for execution of remote access software to detect abnormal use of programs running as a portable executable [CPG 2.T].
  • Using security software to detect instances of remote access software being loaded only in memory.
  • Requiring authorized remote access solutions to be used only from within your network over approved remote access solutions, such as virtual private networks (VPNs) or virtual desktop interfaces (VDIs).
  • Blocking both inbound and outbound connections on common remote access software ports and protocols at the network perimeter.
• Implement application controls to manage and control execution of software, including allowlisting remote access programs.
  • Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation.
• Strictly limit the use of RDP and other remote desktop services. If RDP is necessary, rigorously apply best practices, for example [CPG 2.W]:
  • Audit the network for systems using RDP.
  • Close unused RDP ports.
  • Enforce account lockouts after a specified number of attempts.
  • Apply phishing-resistant multifactor authentication (MFA).
  • Log RDP login attempts.
• Disable command-line and scripting activities and permissions [CPG 2.N].
• Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts [CPG 4.C].
• Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege (PoLP) [CPG 2.E].
• Reduce the threat of credential compromise via the following:
  • Place domain admin accounts in the protected users’ group to prevent caching of password hashes locally.
  • Refrain from storing plaintext credentials in scripts.
• Implement time-based access for accounts set at the admin level and higher [CPG 2.A, 2.E].

In addition, the authoring authorities of this CSA recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques, and to reduce the impact and risk of compromise by ransomware or data extortion actors:

• 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).
• Maintain offline backups of data and regularly maintain backup and restoration (daily or weekly at minimum). By instituting this practice, an organization limits the severity of disruption to its business practices [CPG 2.R].
• Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with NIST’s standards for developing and managing password policies.
  • Use longer passwords consisting of at least eight characters and no more than 64 characters in length [CPG 2.B].
  • Store passwords in hashed format using industry-recognized password managers.
  • Add password user “salts” to shared login credentials.
  • Avoid reusing passwords [CPG 2.C].
  • Implement multiple failed login attempt account lockouts [CPG 2.G].
  • 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 phishing-resistant multifactor authentication (MFA) for all services to the extent possible, particularly for webmail, virtual private networks (VPNs), and accounts that access critical systems [CPG 2.H].
• 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 known exploited vulnerabilities in internet-facing systems [CPG 1.E].
• 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 [CPG 2.F].
• 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 and activity, including lateral movement, 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 [CPG 3.A].
• Install, regularly update, and enable real time detection for antivirus software on all hosts.
• Disable unused ports and protocols [CPG 2.V].
• Consider adding an email banner to emails received from outside your organization [CPG 2.M].
• Disable hyperlinks in received emails.
• Ensure all backup data is encrypted, immutable (i.e., ensure backup data cannot be altered or deleted), and covers the entire organization’s data infrastructure [CPG 2.K, 2.L, 2.R].

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, FBI and CISA 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. FBI and CISA 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 Tables 4-16).
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.

FBI and CISA 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

• Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
• Resource to mitigate a ransomware attack: #StopRansomware Guide.
• No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from IP addresses, a sample ransom note, communications with Snatch threat actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. The FBI and CISA 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 the FBI Internet Crime Complaint Center (IC3) at ic3.gov, a local FBI Field Office, or to CISA at report@cisa.gov or (888) 282-0870.

REFERENCES

[1] DataBreaches.net

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI and CISA do not endorse any commercial entity, 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 FBI or CISA.

VERSION HISTORY

September 20, 2023: Initial version.

Source de l’article sur us-cert.gov

SUMMARY

The Cybersecurity and Infrastructure Security Agency (CISA) and Federal Bureau of Investigation (FBI) are releasing this joint Cybersecurity Advisory (CSA) to disseminate QakBot infrastructure indicators of compromise (IOCs) identified through FBI investigations as of August 2023. On August 25, FBI and international partners executed a coordinated operation to disrupt QakBot infrastructure worldwide. Disruption operations targeting QakBot infrastructure resulted in the botnet takeover, which severed the connection between victim computers and QakBot command and control (C2) servers. The FBI is working closely with industry partners to share information about the malware to maximize detection, remediation, and prevention measures for network defenders.

CISA and FBI encourage organizations to implement the recommendations in the Mitigations section to reduce the likelihood of QakBot-related activity and promote identification of QakBot-facilitated ransomware and malware infections. Note: The disruption of QakBot infrastructure does not mitigate other previously installed malware or ransomware on victim computers. If potential compromise is detected, administrators should apply the incident response recommendations included in this CSA and report key findings to a local FBI Field Office or CISA at cisa.gov/report.

Download the PDF version of this report:

For a downloadable copy of IOCs, see:

TECHNICAL DETAILS

Overview

QakBot—also known as Qbot, Quackbot, Pinkslipbot, and TA570—is responsible for thousands of malware infections globally. QakBot has been the precursor to a significant amount of computer intrusions, to include ransomware and the compromise of user accounts within the Financial Sector. In existence since at least 2008, QakBot feeds into the global cybercriminal supply chain and has deep-rooted connections to the criminal ecosystem. QakBot was originally used as a banking trojan to steal banking credentials for account compromise; in most cases, it was delivered via phishing campaigns containing malicious attachments or links to download the malware, which would reside in memory once on the victim network.

Since its initial inception as a banking trojan, QakBot has evolved into a multi-purpose botnet and malware variant that provides threat actors with a wide range of capabilities, to include performing reconnaissance, engaging in lateral movement, gathering and exfiltrating data, and delivering other malicious payloads, including ransomware, on affected devices. QakBot has maintained persistence in the digital environment because of its modular nature. Access to QakBot-affected (victim) devices via compromised credentials are often sold to further the goals of the threat actor who delivered QakBot.

QakBot and affiliated variants have targeted the United States and other global infrastructures, including the Financial Services, Emergency Services, and Commercial Facilities Sectors, and the Election Infrastructure Subsector. FBI and CISA encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood of QakBot-related infections and promote identification of QakBot-induced ransomware and malware infections. Disruption of the QakBot botnet does not mitigate other previously installed malware or ransomware on victim computers. If a potential compromise is detected, administrators should apply the incident response recommendations included in this CSA and report key findings to CISA and FBI.

QakBot Infrastructure

QakBot’s modular structure allows for various malicious features, including process and web injection, victim network enumeration and credential stealing, and the delivery of follow-on payloads such as Cobalt Strike^[1], Brute Ratel, and other malware. QakBot infections are particularly known to precede the deployment of human-operated ransomware, including Conti^[2], ProLock^[3], Egregor^[4], REvil^[5], MegaCortex^[6], Black Basta^[7], Royal^[8], and PwndLocker.

Historically, QakBot’s C2 infrastructure relied heavily on using hosting providers for its own infrastructure and malicious activity. These providers lease servers to malicious threat actors, ignore abuse complaints, and do not cooperate with law enforcement. At any given time, thousands of victim computers running Microsoft Windows were infected with QakBot—the botnet was controlled through three tiers of C2 servers.

The first tier of C2 servers includes a subset of thousands of bots selected by QakBot administrators, which are promoted to Tier 1 “supernodes” by downloading an additional software module. These supernodes communicate with the victim computers to relay commands and communications between the upstream C2 servers and the infected computers. As of mid-June 2023, 853 supernodes have been identified in 63 countries, which were active that same month. Supernodes have been observed frequently changing, which assists QakBot in evading detection by network defenders. Each bot has been observed communicating with a set of Tier 1 supernodes to relay communications to the Tier 2 C2 servers, serving as proxies to conceal the main C2 server. The Tier 3 server controls all of the bots.

Indicators of Compromise

FBI has observed the following threat actor tactics, techniques, and procedures (TTPs) in association with OakBot infections:

1. QakBot sets up persistence via the Registry Run Key as needed. It will delete this key when running and set it back up before computer restart: HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionRun
2. QakBot will also write its binary back to disk to maintain persistence in the following folder: C:UsersAppDataRoamingMicrosoft
3. QakBot will write an encrypted registry configuration detailing information about the bot to the following registry key: HKEY_CURRENT_USERSoftwareMicrosoft

In addition, the below IP addresses were assessed to have obtained access to victim computers. Organizations are encouraged to review any connections with these IP addresses, which could potentially indicate a QakBot and/or follow-on malware infection.

Disclaimer: The below IP addresses are assessed to be inactive as of August 29, 2023. Several of these observed IP addresses were first observed as early as 2020, although most date from 2022 or 2023, and have been historically linked to QakBot. FBI and CISA recommend these IP addresses be investigated or vetted by organizations prior to taking action, such as blocking.

Table 1: IPs Affiliated with QakBot Infections

IP Address	First Seen
85.14.243[.]111	April 2020
51.38.62[.]181	April 2021
51.38.62[.]182	December 2021
185.4.67[.]6	April 2022
62.141.42[.]36	April 2022
87.117.247[.]41	May 2022
89.163.212[.]111	May 2022
193.29.187[.]57	May 2022
193.201.9[.]93	June 2022
94.198.50[.]147	August 2022
94.198.50[.]210	August 2022
188.127.243[.]130	September 2022
188.127.243[.]133	September 2022
94.198.51[.]202	October 2022
188.127.242[.]119	November 2022
188.127.242[.]178	November 2022
87.117.247[.]41	December 2022
190.2.143[.]38	December 2022
51.161.202[.]232	January 2023
51.195.49[.]228	January 2023
188.127.243[.]148	January 2023
23.236.181[.]102	Unknown
45.84.224[.]23	Unknown
46.151.30[.]109	Unknown
94.103.85[.]86	Unknown
94.198.53[.]17	Unknown
95.211.95[.]14	Unknown
95.211.172[.]6	Unknown
95.211.172[.]7	Unknown
95.211.172[.]86	Unknown
95.211.172[.]108	Unknown
95.211.172[.]109	Unknown
95.211.198[.]177	Unknown
95.211.250[.]97	Unknown
95.211.250[.]98	Unknown
95.211.250[.]117	Unknown
185.81.114[.]188	Unknown
188.127.243[.]145	Unknown
188.127.243[.]147	Unknown
188.127.243[.]193	Unknown
188.241.58[.]140	Unknown
193.29.187[.]41	Unknown

Organizations are also encouraged to review the Qbot/QakBot Malware presentation from the U.S. Department of Health & Human Services Cybersecurity Program for additional information.

MITRE ATT&CK TECHNIQUES

For detailed associated software descriptions, tactics used, and groups that have been observed using this software, see MITRE ATT&CK’s page on QakBot.^[9]

MITIGATIONS

Note: For situational awareness, the following SHA-256 hash is associated with FBI’s QakBot uninstaller: 7cdee5a583eacf24b1f142413aabb4e556ccf4ef3a4764ad084c1526cc90e117

CISA and FBI recommend network defenders apply the following mitigations to reduce the likelihood of QakBot-related activity and promote identification of QakBot-induced ransomware and malware infections. Disruption of the QakBot botnet does not mitigate other already-installed malware or ransomware on victim computers. Note: These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats and TTPs. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

Best Practice Mitigation Recommendations

• 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) [CPG 2.O, 2.R, 5.A].
• Require all accounts with password logins (e.g., service accounts, admin accounts, and domain admin accounts) to comply with NIST’s standards when developing and managing password policies [CPG 2.B]. This includes:
  • 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.
• Use phishing-resistant multi-factor authentication (MFA) [CPG 2.H] (e.g., security tokens) for remote access and access to any sensitive data repositories. Implement phishing-resistant MFA for as many services as possible—particularly for webmail and VPNs—for accounts that access critical systems and privileged accounts that manage backups. MFA should also be used for remote logins. For additional guidance on secure MFA configurations, visit cisa.gov/MFA and CISA’s Implementing Phishing-Resistant MFA Factsheet.
• 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 known exploited vulnerabilities of internet-facing systems [CPG 1.E]. CISA offers a range of services at no cost, including scanning and testing to help organizations reduce exposure to threats via mitigating attack vectors. Specifically, Cyber Hygiene services can help provide a second-set of eyes on organizations’ internet-accessible assets. Organizations can email vulnerability@cisa.dhs.gov with the subject line, “Requesting Cyber Hygiene Services” to get started.
• 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 to restrict adversary lateral movement [CPG 2.F].
• Identify, detect, and investigate abnormal activity and potential traversal of the indicated malware with a networking monitoring tool. To aid in detecting the malware, 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 [CPG 3.A].
• 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 [CPG 2.D, 2.E].
• Disable unused ports [CPG 2.V, 2.W, 2X].
• 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 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 [CPG 2.E].
• 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.
• Perform regular secure system backups and create known good copies of all device configurations for repairs and/or restoration. Store copies off-network in physically secure locations and test regularly [CPG 2.R].
• Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.

Ransomware Guidance

• CISA.gov/stopransomware is a whole-of-government resource that serves as one central location for ransomware resources and alerts.
• CISA, FBI, the National Security Agency (NSA), and Multi-State Information Sharing and Analysis Center (MS-ISAC) published an updated version of the #StopRansomware Guide, as ransomware actors have accelerated their tactics and techniques since its initial release in 2020.
• CISA has released a new module in its Cyber Security Evaluation Tool (CSET), the Ransomware Readiness Assessment (RRA). CSET is a desktop software tool that guides network defenders through a step-by-step process to evaluate cybersecurity practices on their networks.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA and FBI 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. CISA and FBI also 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 MITRE ATT&CK’s page on QakBot).^[9]
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.

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

REPORTING

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 QakBot-affiliated actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. 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, FBI and CISA urge you to promptly report ransomware incidents to a local FBI Field Office or CISA at cisa.gov/report.

RESOURCES

• HHS: Qbot/QakBot Malware
• CISA: CPGs
• NIST: 800-63B Digital Identity Guidelines
• CISA: MFA
• CISA: Implementing Phishing-Resistant MFA
• CISA: Known Exploited Vulnerabilities Catalog
• CISA: Cyber Hygiene
• CISA: Zero Trust
• CISA: #StopRansomware
• CISA: #StopRansomware Guide
• CISA: CSET Tool Sets Sights on Ransomware Threat

REFERENCES

1. MITRE: Cobalt Strike
2. MITRE: Conti
3. MITRE: ProLock
4. MITRE: Egregor
5. MITRE: REvil
6. MITRE: MegaCortex
7. MITRE: Black Basta
8. MITRE: Royal
9. MITRE: QakBot

DISCLAIMER

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

VERSION HISTORY

August 30, 2023: Initial version.

Source de l’article sur us-cert.gov

SUMMARY

The Cybersecurity and Infrastructure Security Agency (CISA) and the Norwegian National Cyber Security Centre (NCSC-NO) are releasing this joint Cybersecurity Advisory (CSA) in response to active exploitation of CVE-2023-35078 and CVE-2023-35081. Advanced persistent threat (APT) actors exploited CVE-2023-35078 as a zero day from at least April 2023 through July 2023 to gather information from several Norwegian organizations, as well as to gain access to and compromise a Norwegian government agency’s network.

Ivanti released a patch for CVE-2023-35078 on July 23, 2023. Ivanti later determined actors could use CVE-2023-35078 in conjunction with another vulnerability CVE-2023-35081 and released a patch for the second vulnerability on July 28, 2023. NCSC-NO observed possible vulnerability chaining of CVE-2023-35081 and CVE-2023-35078.

CVE-2023-35078 is a critical vulnerability affecting Ivanti Endpoint Manager Mobile (EPMM) (formerly known as MobileIron Core). The vulnerability allows threat actors to access personally identifiable information (PII) and gain the ability to make configuration changes on compromised systems. CVE-2023-35081 enables actors with EPMM administrator privileges to write arbitrary files with the operating system privileges of the EPMM web application server. Threat actors can chain these vulnerabilities to gain initial, privileged access to EPMM systems and execute uploaded files, such as webshells.

Mobile device management (MDM) systems are attractive targets for threat actors because they provide elevated access to thousands of mobile devices, and APT actors have exploited a previous MobileIron vulnerability. Consequently, CISA and NCSC-NO are concerned about the potential for widespread exploitation in government and private sector networks.

This CSA provides indicators of compromise (IOCs) and tactics, techniques, and procedures (TTPs) obtained by NCSC-NO investigations. The CSA also includes a nuclei template to identify unpatched devices and detection guidance organizations can use to hunt for compromise. CISA and NCSC-NO encourage organizations to hunt for malicious activity using the detection guidance in this CSA. If potential compromise is detected, organizations should apply the incident response recommendations included in this CSA. If no compromise is detected, organizations should still immediately apply patches released by Ivanti.

Download the PDF version of this report:

Download the .xml or .json file associated with this report:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK^® for Enterprise framework, version 13. See the MITRE ATT&CK Tactics and Techniques section of this advisory for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Overview

In July 2023, NCSC-NO became aware of APT actors exploiting a zero-day vulnerability in Ivanti Endpoint Manager (EPMM), formerly known as MobileIron Core, to target a Norwegian government network. Ivanti confirmed that the threat actors exploited CVE-2023-35078 and released a patch on July 23, 2023.[1] Ivanti later determined actors could use CVE-2023-35078 in conjunction with another vulnerability, CVE-2023-35081, and released a patch for the second vulnerability on July 28, 2023.[2]

CVE-2023-35078 is a critical authentication bypass [CWE-288] vulnerability affecting Ivanti Endpoint Manager Mobile (EPMM), formerly known as MobileIron Core. The vulnerability allows unauthenticated access to specific application programming interface (API) paths. Threat actors with access to these API paths can access PII such as names, phone numbers, and other mobile device details of users on the vulnerable system; make configuration changes to vulnerable systems; push new packages to mobile endpoints; and access Global Positioning System (GPS) data if enabled.

According to Ivanti, CVE-2023-35078 can be chained with a second vulnerability CVE-2023-35081.[2] CVE-2023-35081 is directory traversal vulnerability [CWE-22] in EPMM. This vulnerability allows threat actors with EPMM administrator privileges the capability to write arbitrary files, such as webshells, with operating system privileges of the EPMM web application server. The actors can then execute the uploaded file.[2]

CISA added CVE-2023-35078 to its Known Exploited Vulnerabilities Catalog on July 25, 2023, and CVE-2023-35081 on July 31, 2023.

CISA and NCSC-NO are concerned about the potential for widespread exploitation of both vulnerabilities in government and private sector networks because MDM systems provide elevated access to thousands of mobile devices. Threat actors, including APT actors, have previously exploited a MobileIron vulnerability [3],[4].

APT Actor Activity

The APT actors have exploited CVE-2023-35078 since at least April 2023. The actors leveraged compromised small office/home office (SOHO) routers, including ASUS routers, to proxy [T1090] to target infrastructure, and NCSC-NO observed the actors exploiting CVE-2023-35078 to obtain initial access to EPMM devices [T1190] and:

• Perform arbitrary Lightweight Directory Access Protocol (LDAP) queries against the Active Directory (AD).
• Retrieve LDAP endpoints [T1018].
• Use API path /mifs/aad/api/v2/authorized/users to list users and administrators [T1087.002] on the EPMM device.
• Make EPMM configuration changes (Note: It is unknown what configuration changes the actors made).
• Regularly check EPMM Core audit logs [T1005].

The APT actors deleted some of their entries in Apache httpd logs [T1070] using mi.war, a malicious Tomcat application that deletes log entries based on the string in keywords.txt. The actors deleted log entries with the string Firefox/107.0.

The APT actors used Linux and Windows user agents with Firefox/107.0 to communicate with EPMM. Other agents were used; however, these user agents did not appear in the device logs. It is unconfirmed how the threat actors ran shell commands on the EPMM device; however, NCSC-NO suspects the actors exploited CVE-2023-35081 to upload webshells on the EPMM device and run commands [T1059].

The APT actors tunneled traffic [T1572] from the internet through Ivanti Sentry, an application gateway appliance that supports EPMM, to at least one Exchange server that was not accessible from the internet [T1090.001]. It is unknown how they tunneled traffic. NCSC-NO observed that the network traffic used the TLS certificate of the internal Exchange server. The APT actors likely installed webshells [T1505.003] on the Exchange server in the following paths [T1036.005]:

• /owa/auth/logon.aspx
• /owa/auth/logoff.aspx
• /owa/auth/OutlookCN.aspx

NCSC-NO also observed mi.war on Ivanti Sentry but do not know how the actors placed it there.

MITRE ATT&CK TACTICS AND TECHNIQUES

See Table 1—Table 7 for all referenced threat actor tactics and techniques in this advisory.

Table 1: APT Actors ATT&CK Techniques for Initial Access

Technique Title	ID	Use
Exploit Public-Facing Application	T1190	The APT actors exploited CVE-2023-35078 in public facing Ivanti EPMM appliances since at least April 2023.

Table 2: APT Actors ATT&CK Techniques for Execution

Technique Title	ID	Use
Command and Scripting Interpreter	T1059	The APT actors may have exploited CVE-2023-35081 to upload webshells on the EPMM device and run commands.

Table 3: APT Actors ATT&CK Techniques for Discovery

Technique Title	ID	Use
Account Discovery: Domain Account	T1087.002	The APT actors exploited CVE-2023-35078 to gather EPMM device users and administrators.
Remote System Discovery	T1018	The APT actors retrieved LDAP endpoints.

Table 4: APT Actors ATT&CK Techniques for Persistence

Technique Title	ID	Use
Masquerading: Match Legitimate Name or Location	T1036.005	The APT actors likely installed webshells at legitimate Exchange server paths.
Server Software Component: Web Shell	T1505.003	The APT actors implanted webshells on the compromised infrastructure.

Table 5: APT Actor ATT&CK Techniques for Defense Evasion

Technique Title	ID	Use
Indicator Removal	T1070	APT actors deleted httpd access logs after the malicious activities took place using string Firefox/107.0.

Table 6: APT Actor ATT&CK Techniques for Collection

Technique Title	ID	Use
Data from Local System	T1005	APT actors regularly checked EPMM Core audit logs.

Table 7: APT Actor ATT&CK Techniques for Command and Control

Technique Title	ID	Use
Protocol Tunneling	T1572	The APT actors tunneled traffic from the internet to an Exchange server that was not accessible from the internet.
Proxy	T1090	The actors leveraged compromised SOHO routers to proxy to and compromise infrastructure. The actors tunneled traffic from the internet to at least one Exchange server.
Proxy: Internal Proxy	T1090.001	The APT actors tunneled traffic from the internet to an Exchange server that was not accessible from the internet.

EVIDENCE OF VULNERABILITY METHODS

CISA recommends administrators use the following CISA-developed nuclei template to determine vulnerability to CVE-2023-30578:

id: CVE-2023-35078-Exposure   info:   name: Ivanti EPMM Remote Unauthenticated API Access   author: JC   severity: critical   reference:     - https://nvd.nist.gov/vuln/detail/CVE-2023-35078   description: Identifies vulnerable instances of Ivanti Endpoint Manager Mobile (EPMM), formerly MobileIron Core, through 11.10 allows remote attackers to obtain PII, add an administrative account, and change the configuration because of an authentication bypass.   tags: ivanti, mobileiron, epmm, auth-bypass   requests:   - method: GET     path:       - "{{RootURL}}/mifs/aad/api/v2/ping"       matchers-condition: and     matchers:                           - type: status         status:           - 200               - type: word         part: body         words:           - "vspVersion"           - "apiVersion"         condition: and

CISA recommends administrators use the following CISA-developed nuclei template to determine vulnerability to CVE-2023-35081:

id: CVE-2023-35081   info:   name: Ivanti EPMM Remote Arbitrary File Write   author: JC   severity: High   reference:     - https://nvd.nist.gov/vuln/detail/CVE-2023-35081   description: Identifies vulnerable unpatched versions of Ivanti Endpoint Manager Mobile (EPMM), formerly MobileIron Core, through 11.10.0.3, 11.9.1.2, and 11.8.1.2 that allows an authenticated administrator to perform arbitrary file writes to the EPMM server.   tags: ivanti, mobileiron, epmm   requests:   - method: GET     path:       - "{{RootURL}}/mifs/c/windows/api/v2/device/registration"       matchers-condition: and     matchers:                           - type: status         status:           - 200               - type: regex         part: all         regex:           - '.*?VSP ((0?[0-9]|10)(.d+){1,3}|11.(0?[0-7])(.d+){1,2}|11.8.0(.d+)?|11.8.1.[0-1]|11.9.0(.d+)?|11.9.1.[0-1]|11.10.0.[0-2]).*'

Run the following NCSC-NO-created checks to check for signs of compromise:

1. Investigate logs in centralized logging solutions or forwarded syslogs from EPMM devices for any occurrences of /mifs/aad/api/v2/.
2. Look for spikes or an increase of EventCode=1644 in the AD since at least April 2023. The LDAP queries performed by EPMM when the threat actor used the MIFS API generated tens of millions of this event code. Also look for EventCodes 4662, 5136, and 1153.
3. To detect tunneling activity through Sentry, look for traffic from EPMM devices to other internal servers, as well as TLS traffic towards instances of EPMM with different TLS certificates than the instance itself would possess. Traffic to EPMM with certificates originating from endpoints further inside the network, e.g. standard Windows generated certificates such as CN=EXCHANGE01 or similar.
4. Perform forensic analysis of disk and memory since log retention may be poor and threat actors have been observed deleting log entries. Pay particular attention to unallocated disk space (free space on filesystem).
5. Check for activity from ASUS routers in your own country towards EPMM and Sentry devices.

INCIDENT RESPONSE

If compromise is detected, organizations should:

1. Quarantine or take offline potentially affected hosts.
2. Reimage compromised hosts.
3. Provision new account credentials.
4. Collect and review artifacts such as running processes/services, unusual authentications, and recent network connections.
5. Report the compromise to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870) or to NCSC-NO via NCSC-NO’s 24/7 Operations Center (cert@ncsc.no or +47 23 31 07 50).

MITIGATIONS

CISA and NCSC-NO recommend organizations:

• Upgrade Ivanti EPMM versions to the latest version as soon as possible. See Ivanti CVE-2023-35081 – Remote Arbitrary File Write for patch information. This patch protects against CVE-2023-35078 and CVE-2023-35081.
  • See the Evidence of Vulnerability Methods section of this advisory for CISA-developed nuclei templates to find any EPMM versions vulnerable to CVE-2023-35078 and CVE-2023-35081.
  • Organizations using unsupported versions (i.e., versions prior to 11.8.1.0) should immediately upgrade to a supported version. If you cannot immediately upgrade, apply the Ivanti-provided RPM fix for CVE-35078 (this workaround does not protect against CVE-2023-35081):
    • Login to command line shell (CLI) in enable mode.
    • Run the following command: # install rpm url https://support.mobileiron.com/ivanti-updates/ivanti-security-update-1.0.0-1.noarch.rp
    • See Ivanti’s Knowledge Base (KB) Remote unauthenticated API access vulnerability – CVE-2023-35078 for more information on the RPM fix.
• Treat MDM systems as high-value assets (HVAs) with additional restrictions and monitoring. MDM systems provide elevated access to thousands of hosts and should be treated as high value assets (HVAs) with additional restrictions and monitoring.
• Follow best cybersecurity practices in production and enterprise environments, including mandating phishing-resistant multifactor authentication (MFA) for all staff and services. For additional best practices, see CISA’s Cross-Sector Cybersecurity Performance Goals (CPGs). The CPGs, developed by CISA and the National Institute of Standards and Technology (NIST), are a prioritized subset of IT and OT security practices that can meaningfully reduce the likelihood and impact of known cyber risks and common TTPs. Because the CPGs are a subset of best practices, CISA and NCSC-NO also recommend software manufacturers implement a comprehensive information security program based on a recognized framework, such as the NIST Cybersecurity Framework (CSF).

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA and NCSC-NO recommends 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. CISA recommends 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–Table 7).
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.

CISA recommends 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.

REFERENCES

[1] Ivanti: CVE-2023-35078 – Remote Unauthenticated API Access Vulnerability

[2] Ivanti: CVE-2023-35081 – Remote Arbitrary File Write

[3] CISA: Potential for China Cyber Response to Heightened U.S.-China Tensions

[4] CISA: Top Routinely Exploited Vulnerabilities

RESOURCES

• Mnemonic: Ivanti Endpoint Manager Mobile (EPMM) Authentication Bypass Vulnerability
• Mnemonic: Threat Advisory: Remote File Write Vulnerability in Ivanti EPMM

ACKNOWLEDGEMENTS

Ivanti contributed to this joint advisory.

NCSC-NO wishes to acknowledge Mnemonic’s contributions.

VERSION HISTORY

August 1, 2023: Initial version.

August 2, 2023: Added stix file, updated Acknowledgements section, and added Resources section.

APPENDIX: INDICATORS OF COMPROMISE

NCSC-NO observed the following webshell hash:

c0b42bbd06d6e25dfe8faebd735944714b421388

NCSC-NO observed the following hash of mi.war:

1cd358d28b626b7a23b9fd4944e29077c265db46

NCSC-NO observed the following JA3 hashes used against MobileIron Core:

2d5bd942ebf308df61e1572861d146f6 473cd7cb9faa642487833865d516e578 579ccef312d18482fc42e2b822ca2430 849d3331f3e07a0797a02f12a6a82aa9 8d9f7747675e24454cd9b7ed35c58707 ad55557b7cbd735c2627f7ebb3b3d493 cd08e31494f9531f560d64c695473da9 e1d8b04eeb8ef3954ec4f49267a783ef e60dc8370ecf78cf115162fbc257baf5 e669667efb41c36f714c309243f41ca7 e84a32d43db750b206cb6beed08281d0 eb5fdc72f0a76657dc6ea233190c4e1c

NCSC-NO observed the following JA3 hashes used against Exchange when tunneling via EPMM Sentry:

0092ce298a1d451fbe93dc4237053a96 00e872019b976e69a874ee7433038754 01ecd9ab9be75e832c83c082be3bdf18 0212a88c7ed149febdefa347c610b248 02be3b93640437dbba47cc7ed5ab7895 03f8852448a85e14f2b4362194160c32 045f8ccdac6d4e769b30da406808da71 04e7f5787f89a597001b50a37b9f8078 070f9fe9f0ec69e6b8791d280fde6a48 07a624d7236cca3934cf1f8e44b74b52 09df72c01a1a0ad193e2fff8e454c9c4 0b28842d64a344c287e6165647f3b3fe 0b8e1211de50d244b89e6c1b366d3ccf 0cb0380cf75a863b3e40a0955b1ada9f 0da24834056873a8cd8311000088e8be 0e1fad8ffaa7a939f0a6cbf9cd7e2fcd 0f6e78839398c245d13f696a3216d840 119f8c9050d1499b6f958b857868b8ce 11c506d5e3fb7e119c4287202c96a930 1336df27f94b25a25acac9db3e61e461 14671c3f8deca7d73a03b74cb854c21d 146caf9bd0153428f54e9ef472154983 14994353f3ea6fd25952a8c7d57f9ecf 151bc875df15d1385e6eb02f9edaba06 15a074a397727b26a846b443b99c20ff 1660f3d882a4311ca013ee4586e01fd9 16a74fc216f8a4ce43466bb83b6d3fd2 188623fdd056c4ed13d1ff34c7377637 19f51486abd40c9f0fc0503559a6c523 1a024e63721c610d2e54e67d62cd5460 1aa7dae8f2ae0a29402ed51819f82db4 1abfdeaadb74a0f7c461e7bab157b17f 1b6720ed0b67c910a80722ce973d6217 1b7d9368c6ce7623fdbc43f013626535 1e0850e10a00c9bbdd5c582ff4cb6833 1ec71612e438cf902913eec993475eb9 206fed3a39d9215c35395663f5bb3307 22cc1b3bc9f99d3a520ae58fee79a0d5 23e3e6fa8b23d9bc19e82de4e64c79e9 253fd4659bf21be116858bc0f206c5b9 276e175d4fe8454c4c47e966d8cb3fa3 289a450c7478dd52a10c6ed2fb47f7e9 2aa8ba7478b1362274666d714df575bc 2beecb6b9e386f29d568229a9953c3d2 2ebc7fdceaa9a0df556e989d77157006 3003024afe64b4e8a5a30825c14bbb12 3082e669dda9d023e2dcd8b9549a84a8 309d33c6f77a3fc75654c44c61596ccd 30a9f568eb3df79352fc587a078623b6 30be84e6b95f44c203f8e7fce7339a8e 3268a5097a543c7dbd82c39a9193b7fe 32775ead3ea1ad7db2f4bea67fe0cabb 34ac9a6ef5d285119abec50fbe41fcfe 34d92552e278710c1e84f0bd8dc3a6b8 361f47a6357cc6e3a9bcdd20cfaaf0e9 3685abc75517e61e47e52e5f2d060f54 3744004013135b9f9a05cb58cda8134d 37d952966ea7e79277803f13d7147544 391a4c2c7541b8b78e2f99bf586e9794 393662e5aa0cb49c5d666a6d10a1ade6 3962b622c5aa815afb803b92aa948424 3b22af324abded2781ed8f6a61f3654f 3b30b4555cc8b4b164ad03cf322cbea8 3bd1bdb5e90b9590a8878bff2ada8204 3be529eb3a7daaf34f963a22188f6139 3dd13faad1c45eb0c23e4567210f7eac 403273b51f91cf3c333695e5532cb2c3 404f56045e436d53ead2177bf957ba39 41854adbc73b0b58e5c566f60bb0df25 43c22dabb1e6d2449a39c2f7e974d537 476e72bbda5b78d188766139889e3038 4898a51256ae7d914a5ffd5695973470 49230c486f0fd383cd301fe162d6a786 4959a611b9885022d81b4bc8e4b1d149 495c6ff7ca0379ad0891bac47917d09a 49d2bd08038dc7dada221008591940f9 4c1b73ec52e6eec0c5d20577fcbc9ef1 4d34db639ba84b11822fb3dac47ed7d1 5244b163f9326a1e5eaa8860f7543f99 539f1a5183800a96228458932f9307f7 5466368d4659f1b1470bcb09e65b484d 549cde6535a884126755fc53f59a820c 555389e92c622b87d3fc395fd8723501 588d0b42e54174a98e1eca59945e8b32 58bc21d305a65c41745327f142f3ac12 59401c9a60449c742d073d93d1b7039a 59eec218522cc5c7743a0d37892a3345 59faf75430e9326d3ae9d231bb3ae8c6 5d0259ca16cfc2d7d1b0fac69f29ab05 5d55026fb84dba91ac01e2095504b1bc 5e35f50c692081fd6c7ddac1272e2d6c 5f4d5965af741bba59b7c8d3425f33dd 6010282004917ecf3900babf61456432 6088c2a04c94cdcd5a283a6d1622ffba 61dee38d2f97220efb1218ad8971e3ab 62ac194f2526eb45485526bca35c8f43 634296a023280d020674c873d0199760 635755dadfab8b92fb502aafb09122db 63fc58be0d7b48eaa34da7f752ae8ae6 6441640409815cfb4bf469e685e1bdb5 646973d1928c401ba80961c12cbf84a2 65eef0a0ee257254ef0418aa57192cfb 66f6a192083a7ab00ae8e0b5cc52e8f4 67a42e2e27ffc26d1f3d0ceb8384afd0 689385f1218e0d4c347595648ca6a776 692f91c0c5e9e93e0a24bd3392887ca1 69ecf52960c8bd9e746dfe9ee19c11f6 6e359f3bbc622e9b1ed36f6e3d521bcf 6e3650528f719fc50988a1f697644832 6ead0d5d3f87911c27f3ae0a75e6b5bc 6f1fa8b444caf0d8238f948279ca74e1 6fb8cdf567dd7d89d53b5771d769cb5f 706b6055658aff067ae370f23831ef6b 708140c311d3d69418f75c928e7535a0 719ec5da8f2153a436ee8567ff609894 7292ef4cdca529071fad97496e1c9439 74871691eac48156ce0da2cfa3ab401a 74cf24f2a66a31c88b6fcfe01f12160c 75e874d8e0a79697633b87ea5e798b1c 76c0d09fed2f33babb0de8ee2c07144c 77a01363fa2b29af25c004da9570e23c 78988c65e9b70e7929e747408d8f0b0e 79c6d12d168b85437384b20eb94e106b 7b4137b4e85f31a81bb5bafeda993947 7b9db1d58326c1fa276ba2a39bcc2617 7cbc7459db5327c26476549f225030f5 7cd727171c2522f51417edeeba4f1791 7e3630c67c802eabb67b108ad4d7ded7 802f5d34c230da40c0912a1c5a9b702b 80bd0f3610f6c4d60584a5be0b8a3016 819030799f0020ed724c2ef3ffaa56c6 8207129585da68066ed08e94216d76ee 821f649d08687e22f96cea99fbb5d3a3 830838cb0620d659405a74401cd72557 833d3201066f5184c874c73a2083c448 840f488b7c0a5d686d1e89908735f354 84301b967a4d9a242466c04901bad691 85c3fac6a9885362c448f434671e362f 883b9fe16e45c388968defc73a5fba7a 8a6b0ba3496eeca39d6d3f9bae830c90 8ad0fd4b78c89bd63b97343fda1eeccb 8b0ae9029974091df12210255aaecad6 8b297f8b219e968932293ee7a8242ca3 8bb1781e756a53cd00d9b2ec670fa21e 8d5515351afdf27b013f96a05bf45147 8fafa73e9985e05d0c1c964da770c567 905967b08bd44cfa60d969229921ac23 9188ef45ea917a91ec9b92b5dd8cd90d 918dfab0333ae15d61f14fd24b5eaaac 922a3272aad17c9eaad733696a4321da 9253399537fad8448f1d4732dd79f6fa 934a8a6528e91caa019acb76e791a71d 95588e0386206fa02912cfcaf18c1220 9610328cdaa4694800c2c93410f8ce82 9622902cc43f4a20d0d686a37e4d8232 96c41e4c4a1812187fb279b9299ad63b 984c4653a563b19c87f264611a6adc01 9980febfaf901d4113a1c473f79d7eb6 9a176d818edff838fc057cea3ee372c0 9ba21c5148913186a5bf877078cbc048 9cfda02ef7e04c469b77f8197a249c17 9d74d395bd2f72a47a5c980e6040df5a 9df128ebe0c82064aa746647883112c9 9e5613533972a9d42d2e3344a4e58566 9ec17429eed5446e3720796ab50d8c60 9f2438aaab4744c4b7b5b7287a783099 9f3bf94572344b36f6ef1689cb30c66e 9fdd7a85b3a4ef8ded73beb3e6218109 a1b732a9af792f75a68ed78d72ffb8f6 a260d836428cdb971bdf147ca6940160 a4f11b1eb659869a0ae70898a4a0e5ee a596ebbcf438980c880d711315e4fdf1 a80b6a354b493264f37aa39d0d41b5fc a89df6156eb5a2de196388d4a123b470 a96837fe533247abb7f88000d0216a50 a98cf0a359f430a00f4f3d522f5b6cc0 aa2fe3a253e169b05e1782ca57a688d2 aef0172a2c03f77912de0bbf14aee00f af06c3e72f2f307515ba549174d8e5a6 b311ab82b30f41b12cb9089d00c4a1ff b4f31423445b5f13675f205ac997f41f b50666c9aed1c2f222c56b6e9b326d27 b53f179b3f25f72bb0c7ccf45bf8beee b57f3e41c03803306b0ee2111f7ef823 b79434613820faf30d58f103c4415a29 b8366aaa5ed51c0dea3fc90ef7e14889 b8f6b0d234a305c25411e83fd430c624 b956ed2b848dabb4e79ab7358233861b b9ecb08402df0f1f6e1ce76b8ad6e91f ba4a616c8d4ab9358a82b321d8e618bf bcd62f3e029f96f62c24d50d2d1402ac bcf75736d176394f3df69f3e0ef7dd9f be1f24457141d80206bc2e58f55dc879 c013f308d170aa2eca4a5b0f0bbd3ccb c0a2fd066c955137036f92da2c3a3ff1 c17b3ec40ed5216e44311138aafaea2c c262a39f49604f05a5656213f758cd46 c66f36eb180438882133717c3abb5157 c986c7bf720ce1463c3d628d2b3dad01 c9c16287cbbe5a037244e374ba84aecc cbcd728a2350712b5747cd3447473deb cbeeb123efe8cf7f842426b673415c28 ccb15eef4287c8efa472915bcb4ec458 ccdddb69e9344a039c4ac9c49a6f2d7b cd1312be032256a10cf866af3e9afae9 ce0dd163d9e02bfd42d61024523cb134 ceef2e728db1b5ae15432f844eeb66e1 d12d98a0877f6e3c8b5a59f41cc4de9b d131f17689f1f585e9bfdcdb72a626bb d173076d97a0400a56c81089912b9218 d255291bb8e460626cb906ebacc670e5 d2cea317778ad6412c458a8a33b964fd d3cfee76468a9556fd9d017c1c8ee028 d3d72f4c7038f7313ad0570e16c293bf d485a1b5db2f97dc56500376d677aa89 d662d20507bebc37b99a4d413afa2752 d711d577b9943ab4e2f8a2e06bb963e3 d92e87d2689957765987e2be732d728e d966c6c822122e96f6e9f5f1d4778391 daee31d7cc6e08ead6afad2175989e1d dbb293176747fa1c2e03cbc09433f236 dc26ef761c7ec40591b1fe6e561b521d dc9e6edeb7557bc80be68be15cebb77a dddfbae77336120febd5ad690af3e341 e1f579227327ebb21cde3f9e7511db01 e3c642432a815a07f035e01308aaa8fc e54329351788661f2a8d4677a759fc42 e82b7ad2c05f4617efbc86a78c1e61e9 e99cffa2afa064625f09e1c5aca8f961 ea6bd3db104ca210b5ad947d46134aaf eb277d809a59d39d02605c0edd9333e9 ed82a50d98700179c8ae70429457477a ef35374f4146b3532f0902d6f7f0ef8c ef4c4d79f02ac404f47513d3a73e20c7 f05a5a60ad6f92d6f28fa4f13ded952f f0776dfe17867709fdb0e0183ed71698 f20fbfd508e24d50522eadf0186b03eb f3d751b0585855077b46dfce226cfea1 f4dd9bb28d680a3368136fb3755e7ea9 f804388f302af1f999e4664543c885a1 f8bcc8f99a3afde66d7f5afb5d8f1b43 f8d6f89aecf792e844e72015c9f27c95 f967460f8c6de1cedb180c90c98bfe98 f9d5cc0cbae77ea1a371131f62662b6b fa4f1a3b215888bc5f19b9f91ba37519 fdff2bf247a7dad40bac228853d5a661 fe6e7fac4f0b4f25d215e28ca8a22957 fe9de1cdd645971c5d15ee1873c3ff8d febba89b4b9a9649b3a3bf41c4c7d853

NCSC-NO observed the following user agents communicating with Exchange (OWA and EWS):

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/114.0 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67

NCSC-NO observed the following user agents communicating with Exchange webshell:

Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A306 Safari/6531.22.7 Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7 Mozilla/5.0 (Linux; Android 7.0; Moto C Build/NRD90M.059) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Mobile Safari/537.36 Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.02272.101 Safari/537.36 Mozilla/5.0 (Linux; Android 5.1.1; SAMSUNG SM-J120M Build/LMY47X) AppleWebKit/537.36 (KHTML, Like Gecko) SamsungBrowser/6.4 Chrome/56.0.2924.87 Mobile Safari/537.36 Mozilla/5.0 (iPhone; CPU iPhone OS 9_0_2 like Mac OS X) AppleWebKit/601.1.45 (KHTML, like Gecko) Version/9.0 Mobile/13A452 Safari/601.1

NCSC-NO observed the following user agents communicating with Exchange Autodiscover:

ExchangeServicesClient/15.00.0913.015 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Firefox/114.0 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML  like Gecko) Chrome/114.0.0.0 Safari/537.36 Edg/114.0.0.0

NCSC-NO observed the following user agents communicating with EWS (/ews/Exchange.asmx):

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.114 Safari/537.36 Edg/103.0.1264.49 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67

NCSC-NO observed the following user agent communicating with Exchange (/powershell):

Windows WinRM Client

 

 

Source de l’article sur us-cert.gov

SUMMARY

The Cybersecurity and Infrastructure Security Agency (CISA) is releasing this Cybersecurity Advisory to warn network defenders about exploitation of CVE-2023-3519, an unauthenticated remote code execution (RCE) vulnerability affecting NetScaler (formerly Citrix) Application Delivery Controller (ADC) and NetScaler Gateway. In June 2023, threat actors exploited this vulnerability as a zero-day to drop a webshell on a critical infrastructure organization’s non-production environment NetScaler ADC appliance. The webshell enabled the actors to perform discovery on the victim’s active directory (AD) and collect and exfiltrate AD data. The actors attempted to move laterally to a domain controller but network-segmentation controls for the appliance blocked movement.

The victim organization identified the compromise and reported the activity to CISA and Citrix. Citrix released a patch for this vulnerability on July 18, 2023.

This advisory provides tactics, techniques, and procedures (TTPs) and detection methods shared with CISA by the victim. CISA encourages critical infrastructure organizations to use the detection guidance included in this advisory for help with determining system compromise. If potential compromise is detected, organizations should apply the incident response recommendations provided in this CSA. If no compromise is detected, organizations should immediately apply patches provided by Citrix.

Download the PDF version of this report:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 13. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Overview

In July 2023, a critical infrastructure organization reported to CISA that threat actors may have exploited a zero-day vulnerability in NetScaler ADC to implant a webshell on their non-production NetScaler ADC appliance. Citrix confirmed that the actors exploited a zero-day vulnerability: CVE-2023-3519. Citrix released a patch on July 18, 2023.[1]

CVE-2023-3519

CVE-2023-3519 is an unauthenticated RCE vulnerability affecting the following versions of NetScaler ADC and NetScaler Gateway:[1]

• NetScaler ADC and NetScaler Gateway 13.1 before 13.1-49.13
• NetScaler ADC and NetScaler Gateway 13.0 before 13.0-91.13
• NetScaler ADC and NetScaler Gateway version 12.1, now end of life
• NetScaler ADC 13.1-FIPS before 13.1-37.159
• NetScaler ADC 12.1-FIPS before 12.1-65.36
• NetScaler ADC 12.1-NDcPP before 12.65.36

The affected appliance must be configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or authentication, authorization, and auditing (AAA) virtual server for exploitation.[1]

CISA added CVE-2023-3519 to its Known Exploited Vulnerabilities Catalog on July 19, 2023.

Threat Actor Activity

As part of their initial exploit chain [T1190], the threat actors uploaded a TGZ file [T1105] containing a generic webshell [T1505.003], discovery script [TA0007], and setuid binary [T1548.001] on the ADC appliance and conducted SMB scanning on the subnet [T1046].

The actors used the webshell for AD enumeration [T1016] and to exfiltrate AD data [TA0010]. Specifically, the actors:

• Viewed NetScaler configuration files /flash/nsconfig/keys/updated/* and /nsconfig/ns.conf [T1005]. Note: These configuration files contain an encrypted password that can be decrypted by the key stored on the ADC appliance [T1552.001].
• Viewed the NetScaler decryption keys (to decrypt the AD credential from the configuration file) [T1552.004].
• Used the decrypted AD credential to query the AD via ldapsearch. The actors queried for:
  • Users (objectClass=user) (objectcategory=person) [T1033]
  • Computers (objectClass=computer) [T1018]
  • Groups (objectClass=group) [T1069.002]
  • Subnets (objectClass=subnet)
  • Organizational Units (objectClass=organizationalUnit)
  • Contacts (objectClass=contact)
  • Partitions (objectClass=partition)
  • Trusts (objectClass=trustedDomain) [T1482]
• Used the following command to encrypt discovery data collected via openssl in “tar ball” [T1560.001]: tar -czvf - /var/tmp/all.txt | openssl des3 -salt -k <> -out /var/tmp/test.tar.gz. (A “tar ball” is a compressed and zipped file used by threat actors for collection and exfiltration.)
• Exfiltrated collected data by uploading as an image file [T1036.008] to a web-accessible path [T1074]: cp /var/tmp/test.tar.gz /netscaler/ns_gui/vpn/medialogininit.png.

The actors’ other discovery activities were unsuccessful due to the critical infrastructure organization’s deployment of their NetScaler ADC appliance in a segmented environment. The actors attempted to:

• Execute a subnet-wide curl command to identify what was accessible from within the network as well as potential lateral movement targets.
• Verified outbound network connectivity with a ping command (ping -c 1 google.com) [T1016.001].
• Executed host commands for a subnet-wide DNS lookup.

The actors also attempted to delete their artifacts [TA0005]. The actors deleted the authorization configuration file (/etc/auth.conf)—likely to prevent configured users (e.g., admin) from logging in remotely (e.g., CLI) [T1531]. To regain access to the ADC appliance, the organization would normally reboot into single use mode, which may have deleted artifacts from the device; however, the victim had an SSH key readily available that allowed them into the appliance without rebooting it.

The actors’ post-exploitation lateral movement attempts were also blocked by network-segmentation controls. The actors implanted a second webshell on the victim that they later removed. This was likely a PHP shell with proxying capability. The actors likely used this to attempt proxying SMB traffic to the DC [T1090.001] (the victim observed SMB connections where the actors attempted to use the previously decrypted AD credential to authenticate with the DC from the ADC via a virtual machine). Firewall and account restrictions (only certain internal accounts could authenticate to the DC) blocked this activity.

MITRE ATT&CK TACTICS AND TECHNIQUES

See Table 1–Table 9 for all referenced threat actor tactics and techniques in this advisory.

Table 1: Cyber Threat Actors ATT&CK Techniques for Initial Access

Technique Title	ID	Use
Exploit Public-Facing Application	T1190	The threat actors exploited CVE-2023-3519 to implant a webshell on the organization’s NetScaler ADC appliance.

 

Table 2: Cyber Threat Actors ATT&CK Techniques for Persistence

Technique Title	ID	Use
Server Software Component: Web Shell	T1505.003	The threat actors implanted a generic webshell on the organization’s NetScaler ADC appliance.

 

Table 3: Cyber Threat Actors ATT&CK Techniques for Privilege Escalation

Technique Title	ID	Use
Abuse Elevation Control Mechanism: Setuid and Setgid	T1548.001	As part of their initial exploit chain uploaded a TGZ file contain a setuid binary on the ADC appliance.

 

Table 4: Cyber Threat Actors ATT&CK Techniques for Defense Evasion

Technique Title	ID	Use
Masquerading: Masquerade File Type	T1036.008	The threat actors exfiltrated data by uploading it as an image file to a web-accessible path.

 

Table 5: Cyber Threat Actors ATT&CK Techniques for Credential Access

Technique Title	ID	Use
Unsecured Credentials: Credentials In Files	T1552.001	The threat actors obtained encrypted passwords from NetScaler ADC configuration files, and the decryption key was stored on the ADC appliance.
Unsecured Credentials: Private Keys	T1552.004	The threat actors obtained decryption keys to decrypt the AD credential obtained from the NetScaler ADC configuration files.

 

Table 6: Cyber Threat Actors ATT&CK Techniques for Discovery

Technique Title	ID	Use
Domain Trust Discovery	T1482	The threat actors queried the AD for trusts.
Permission Groups Discovery: Domain Groups	T1069.002	The threat actors quired the AD for groups.
Remote System Discovery	T1018	The threat actors queried the AD for computers. The threat actors attempted to execute a subnet-wide curl command to identify what was accessible from within the network as well as potential lateral movement targets. Network-segmentation controls prevented this activity.
System Network Configuration Discovery	T1016	The actors used a webshell for AD enumeration.
System Network Configuration Discovery: Internet Connection Discovery	T1016.001	The threat actors attempted to verify outbound network connectivity with a ping command and executed host commands for a subnet-wide DNS lookup. Network-segmentation controls prevented this activity.
Network Service Discovery	T1046	The threat actors conducted SMB scanning on the organization’s subnet.
Account Discovery: Domain Account	T1087.002	The threat actors queried the AD for users.

 

Table 7: Cyber Threat Actors ATT&CK Techniques for Collection

Technique Title	ID	Use
Archive Collected Data: Archive via Utility	T1560.001	The threat actors encrypted discovery data collected via openssl in “tar ball.”
Data from Local System	T1005	The threat actors viewed NetScaler ADC configuration files flash/nsconfig/keys/updated/* and /nsconfig/ns.conf.
Data Staged	T1074	The threat actors uploaded data as an image file to a web-accessible path: cp /var/tmp/test.tar.gz /netscaler/ns_gui/vpn/medialogininit.png.

 

Table 8: Cyber Threat Actors ATT&CK Techniques for Command and Control

Technique Title	ID	Use
Ingress Tool Transfer	T1105	The threat actors exploited CVE-2023-3519 to upload a TGZ file containing a generic webshell, discovery script, and setuid binary on the ADC appliance.
Proxy: Internal Proxy	T1090.001	The actors likely used a PHP shell with proxying capability to attempt proxying SMB traffic to the DC (the traffic was blocked by a firewall and account restrictions).

 

Table 9: Cyber Threat Actors ATT&CK Techniques for Impact

Technique Title	ID	Use
Account Access Removal	T1531	The threat actors deleted the authorization configuration file (/etc/auth.conf)—likely to prevent configured users from logging in remotely (e.g., CLI).

 

DETECTION METHODS

Run the following victim-created checks on the ADC shell interface to check for signs of compromise:

1. Check for files newer than the last installation.
2. Modify the -newermt parameter with the date that corresponds to your last installation:
   • find /netscaler/ns_gui/ -type f -name *.php -newermt [YYYYMMDD] -exec ls -l {} ;
   • find /var/vpn/ -type f -newermt [YYYYMMDD] -exec ls -l {} ;
   • find /var/netscaler/logon/ -type f -newermt [YYYYMMDD] -exec ls -l {} ;
   • find /var/python/ -type f -newermt [YYYYMMDD] -exec ls -l {} ;
3. Check http error logs for abnormalities that may be from initial exploit:
   • grep '.sh' /var/log/httperror.log*
   • grep '.php' /var/log/httperror.log*
4. Check shell logs for unusual post-ex commands, for example:
   • grep '/flash/nsconfig/keys' /var/log/sh.log*
5. Look for setuid binaries dropped:
   • find /var -perm -4000 -user root -not -path "/var/nslog/*" -newermt [YYYYMMDD] -exec ls -l {} ;
6. Review network and firewall logs for subnet-wide scanning of HTTP/HTTPS/SMB (80/443/445) originating from the ADC.
7. Review DNS logs for unexpected spike in internal network computer name lookup originating from the ADC (this may indicate the threat actor resolving host post-AD enumeration of computer objects).
8. Review network/firewall logs for unexpected spikes in AD/LDAP/LDAPS traffic originating from the ADC (this may indicate AD/LDAP enumeration).
9. Review number of connections/sessions from NetScaler ADC per IP address for excessive connection attempts from a single IP (this may indicate the threat actor interacting with the webshell).
10. Pay attention to larger outbound transfers from the ADC over a short period of session time as it can be indicative of data exfiltration.
11. Review AD logs for logon activities originating from the ADC IP with the account configured for AD connection. 
12. If logon restriction is configured for the AD account, check event 4625 where the failure reason is “User not allowed to logon at this computer.”
13. Review NetScaler ADC internal logs (sh.log*, bash.log*) for traces of potential malicious activity (some example keywords for grep are provided below): 
    • database.php
    • ns_gui/vpn
    • /flash/nsconfig/keys/updated 
    • LDAPTLS_REQCERT 
    • ldapsearch 
    • openssl + salt
14. Review NetScaler ADC internal access logs (httpaccess-vpn.log*) for 200 successful access of unknown web resources.

INCIDENT RESPONSE

If compromise is detected, organizations should:

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

MITIGATIONS

CISA recommends all organizations:

• Install the relevant updated version of NetScaler ADC and NetScaler Gateway as soon as possible. See Citrix ADC and Citrix Gateway Security Bulletin for CVE-2023-3519, CVE-2023-3466, CVE-2023-3467 for patch information.
• Follow best cybersecurity practices in your production and enterprise environments, including mandating phishing-resistant multifactor authentication (MFA) for all staff and for all services. For additional best practices, see CISA’s Cross-Sector Cybersecurity Performance Goals (CPGs). The CPGs, developed by CISA and the National Institute of Standards and Technology (NIST), are a prioritized subset of information technology (IT) and operational technology (OT) security practices that can meaningfully reduce the likelihood and impact of known cyber risks and common TTPs. Because the CPGs are a subset of best practices, CISA and ACSC also recommend software manufacturers implement a comprehensive information security program based on a recognized framework, such as the NIST Cybersecurity Framework (CSF).
• As a longer-term effort, apply robust network-segmentation controls on NetScaler appliances, and other internet-facing devices.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA recommends 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. CISA recommends 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–Table 9).
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.

CISA recommends 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.

REFERENCES

[1] Citrix Security Bulletin CTX561482: Citrix ADC and Citrix Gateway Security Bulletin for CVE-2023-3519, CVE-2023-3466, CVE-2023-3467

Source de l’article sur us-cert.gov

SUMMARY

The Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), the Multi-State Information Sharing and Analysis Center (MS-ISAC), and the Canadian Centre for Cyber Security (CCCS) are releasing this joint Cybersecurity Advisory (CSA) in response to cyber threat actors leveraging newly identified Truebot malware variants against organizations in the United States and Canada. As recently as May 31, 2023, the authoring organizations have observed an increase in cyber threat actors using new malware variants of Truebot (also known as Silence.Downloader). Truebot is a botnet that has been used by malicious cyber groups like CL0P Ransomware Gang to collect and exfiltrate information from its target victims.

Previous Truebot malware variants were primarily delivered by cyber threat actors via malicious phishing email attachments; however, newer versions allow cyber threat actors to also gain initial access through exploiting CVE-2022-31199—(a remote code execution vulnerability in the Netwrix Auditor application), enabling deployment of the malware at scale within the compromised environment. Based on confirmation from open-source reporting and analytical findings of Truebot variants, the authoring organizations assess cyber threat actors are leveraging both phishing campaigns with malicious redirect hyperlinks and CVE-2022-31199 to deliver new Truebot malware variants.

The authoring organizations recommend hunting for the malicious activity using the guidance outlined in this CSA, as well as applying vendor patches to Netwrix Auditor (version 10.5—see Mitigations section below).[1] Any organization identifying indicators of compromise (IOCs) within their environment should urgently apply the incident responses and mitigation measures detailed in this CSA and report the intrusion to CISA or the FBI.

Download the PDF version of this report:

Read the associated Malware Analysis Report MAR-10445155-1.v1 Truebot Activity Infects U.S. and Canada Based Networks or download the PDF version below:

For a downloadable copy of IOCs in .xml and .json format, see:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 13. See the MITRE ATT&CK Tactics and Techniques section below for cyber threat actors’ activity mapped to MITRE ATT&CK tactics and techniques.

Initial Access and Execution

In recent months, open source reporting has detailed an increase in Truebot malware infections, particularly cyber threat actors using new tactics, techniques, and procedures (TTPs), and delivery methods.[2] Based on the nature of observed Truebot operations, the primary objective of a Truebot infection is to exfiltrate sensitive data from the compromised host(s) for financial gain [TA0010].

• Phishing:
  • Cyber threat actors have historically used malicious phishing emails as the primary delivery method of Truebot malware, which tricks recipients into clicking a hyperlink to execute malware. Cyber threat actors have further been observed concealing email attachments (executables) as software update notifications [T1189] that appear to be legitimate [T1204.002], [T1566.002]. Following interaction with the executable, users will be redirected to a malicious web domain where script files are then executed. Note: Truebot malware can be hidden within various, legitimate file formats that are used for malicious purposes [T1036.008].[3]
• Exploitation of CVE-2022-31199:
  • Though phishing remains a prominent delivery method, cyber threat actors have shifted tactics, exploiting, in observable manner, a remote code execution vulnerability (CVE-2022-31199) in Netwrix Auditor [T1190]—software used for on-premises and cloud-based IT system auditing. Through exploitation of this CVE, cyber threat actors gain initial access, as well as the ability to move laterally within the compromised network [T1210].

Following the successful download of the malicous file, Truebot renames itself and then loads FlawedGrace onto the host. Please see the FlawedGrace section below for more information on how this remote access tool (RAT) is used in Truebot operations.

After deployment by Truebot, FlawedGrace is able to modify registry [T1112] and print spooler programs [T1547.012] that control the order that documents are loaded to a print queue. FlawedGrace manipulates these features to both escalate privilege and establish persistence.

During FlawedGrace’s execution phase, the RAT stores encrypted payloads [T1027.009] within the registry. The tool can create scheduled tasks and inject payloads into msiexec.exe and svchost.exe, which are command processes that enable FlawedGrace to establish a command and control (C2) connection to 92.118.36[.]199, for example, as well as load dynamic link libraries (DLLs) [T1055.001] to accomplish privilege escalation.

Several hours post initial access, Truebot has been observed injecting Cobalt Strike beacons into memory [T1055] in a dormant mode for the first few hours prior to initiating additional operations. Please see the Cobalt Strike section below for more information on how this remote access tool (RAT) is used in Truebot operations.

Discovery and Defense Evasion

During the first stage of Truebot’s execution process, it checks the current version of the operating system (OS) with RtlGetVersion and processor architecture using GetNativeSystemInfo [T1082].[4] Note: This variant of Truebot malware is designed with over one gigabyte (GB) of junk code which functions to hinder detection and analysis efforts [T1027.001].

Following the initial checks for system information, Truebot has the capability to enumerate all running processes [T1057], collect sensitive local host data [T1005], and send this data to an encoded data string described below for second-stage execution. Based on IOCs in table 1, Truebot also has the ability to discover software security protocols and system time metrics, which aids in defense evasion, as well as enables synchronization with the compromised system’s internal clock to facilitate scheduling tasks [T1518.001][T1124].

Next, it uses a .JSONIP extension, (e.g., IgtyXEQuCEvAM.JSONIP), to create a thirteen character globally unique identifier (GUID)—a 128-bit text string that Truebot uses to label and organize the data it collects [T1036].

After creating the GUID, Truebot compiles and enumerates running process data into either a base64 or unique hexadecimal encoded string [T1027.001]. Truebot’s main goal is identifying the presence of security debugger tools. However, the presence of identified debugger tools does not change Truebot’s execution process—the data is compiled into a base64 encoded string for tracking and defense evasion purposes [T1082][T1622].

Data Collection and Exfiltration

Following Truebot’s enumeration of running processes and tools, the affected system’s computer and domain name [T1082][T1016], along with the newly generated GUID, are sent to a hard-coded URL in a POST request (as observed in the user-agent string). Note: A user-agent string is a customized HTTP request that includes specific device information required for interaction with web content. In this instance, cyber threat actors can redirect victims to malicious domains and further establish a C2 connection.

The POST request functions as means for establishing a C2 connection for bi-lateral communication. With this established connection, Truebot uses a second obfuscated domain to receive additional payloads [T1105], self-replicate across the environment [T1570], and/or delete files used in its operations [T1070.004]. Truebot malware has the capability to download additional malicious modules [T1105], load shell code [T1620], and deploy various tools to stealthily navigate an infected network.

Associated Delivery Vectors and Tools

Truebot has been observed in association with the following delivery vectors and tools:

Raspberry Robin (Malware)

Raspberry Robin is a wormable malware with links to other malware families and various infection methods, including installation via USB drive [T1091].[5] Raspberry Robin has evolved into one of the largest malware distribution platforms and has been observed deploying Truebot, as well as other post-compromise payloads such as IcedID and Bumblebee malware.[6] With the recent shift in Truebot delivery methods from malicious emails to the exploitation of CVE-2022-31199, a large number of Raspberry Robin infections have leveraged this exploitable CVE.[2]

Flawed Grace (Malware)

FlawedGrace is a remote access tool (RAT) that can receive incoming commands [T1059] from a C2 server sent over a custom binary protocol [T1095] using port 443 to deploy additional tools [T1105].[7] Truebot malware has been observed leveraging (and dropping) FlawedGrace via phishing campaigns as an additional payload [T1566.002].[8] Note: FlawedGrace is typically deployed minutes after Truebot malware is executed.

Cobalt Strike (Tool)

Cobalt Strike is a popular remote access tool (RAT) that cyber threat actors have leveraged—in an observable manner—for a variety of post-exploitation means. Typically a few hours after Truebot’s execution phase, cyber threat actors have been observed deploying additional payloads containing Cobalt Strike beacons for persistence and data exfiltration purposes [T1059].[2] Cyber threat actors use Cobalt Strike to move laterally via remote service session hijacking [T1563.001][T1563.002], collecting valid credentials through LSASS memory credential dumping, or creating local admin accounts to achieve pass the hash alternate authentication [T1003.001][T1550.002].

Teleport (Tool)

Cyber threat actors have been observed using a custom data exfiltration tool, which Talos has named “Teleport.”[2] Teleport is known to evade detection during data exfiltration by using an encryption key hardcoded in the binary and a custom communication protocol [T1095] that encrypts data using advanced encryption standard (AES) and a hardcoded key [T1048][T1573.002]. Furthermore, to maintain its stealth, Teleport limits the data it collects and syncs with outbound organizational data/network traffic [T1029][T1030].

Truebot Malware Indicators of Compromise (IOCs)

Truebot IOCs from May 31, 2023, contain IOCs from cyber threat actors conducting Truebot malspam campaigns. Information is derived from a trusted third party, they observed cyber threat actors from 193.3.19[.]173 (Russia) using a compromised local account to conduct phishing campaigns on May 23, 2023 and spread malware through: https[:]//snowboardspecs[.]com/nae9v, which then promptly redirects the user to: https://www.meditimespharma[.]com/gfghthq/, which a trusted third party has linked to other trending Truebot activity.

After redirecting to https://www.meditimespharma[.]com/gfghthq/, trusted third parties have observed, the cyber threat actors using Truebot to pivot to https://corporacionhardsoft[.]com/images/2/Document_16654.exe, which is a domain associated with snowboardspecs[.]com, as well as malicious phishing campaigns in May 2023 and flagged my numerous security vendors, according to trusted third party reporting. Note: these IOCs are associated with Truebot campaigns used by Graceful Spider to deliver FlawedGrace and LummaStealer payloads in May of 2023.

The malicious file MD5 hash, 6164e9d297d29aa8682971259da06848 is associated with multiple Truebot rooted attack vectors and malware families, and was downloaded from https://corporacionhardsoft.com/images/2/Document_16654[.]exe which was flagged as malicious by numerous security vendors, and during its execution, the malware copies itself to C:IntelRuntimeBroker.exe, and based on trusted third party analysis, is linked to https://essadonio.com/538332[.]php, which is linked to 45.182.189[.]71 (Panama) and is associated with other trending Truebot malware campaigns from May 2023.

Please reference table 1 for IOCs described in the paragraph above.

Table 1: Truebot IOCs from May of 2023
Indicator Type	Indicator	Source
Registrant	GKG[.]NET Domain Proxy Service Administrator	Trusted Third Party
Compromised Account Created:	2022-04-10	Trusted Third Party
Malicious account created	1999-11-09	Trusted Third Party
IP	193.3.19[.]173 (Russia)	Trusted Third Party
URL	https://snowboardspecs[.]com/nae9v	Trusted Third Party
Domain	https://corporacionhardsoft[.]com/images/2/Document_16654.exe	Trusted Third Party
File	Document_16654[.]exe	Trusted Third Party
MD5 Hash	6164e9d297d29aa8682971259da06848	Trusted Third Party
File	Document_may_24_16654[.]exe	Trusted Third Party
File	C:IntelRuntimeBroker[.]exe	Trusted Third Party
URL	https://essadonio.com/538332[.]php	Trusted Third Party
IP	45.182.189[.]71 (Panama)	Trusted Third Party
Account Created	2023-05-18	Trusted Third Party

 

Table 2: Truebot malware IOCs from May of 2023
Indicator Type	Indicator	Source
URL	Secretsdump[.]py#l374	A Truly Graceful Wipe Out
Domain	Secretsdump[.]py	A Truly Graceful Wipe Out
Domain	Imsagentes[.]pe	A Truly Graceful Wipe Out
URL	https://imsagentes[.]pe/dgrjfj/	A Truly Graceful Wipe Out
URL	https://imsagentes[.]pe/dgrjfj	A Truly Graceful Wipe Out
URL	https://hrcbishtek[.]com/{5	A Truly Graceful Wipe Out
URL	https://ecorfan.org/base/sj/document_may_24_16654[.]exe	A Truly Graceful Wipe Out
Domain	Hrcbishtek[.]com	A Truly Graceful Wipe Out
File	F33734DFBBFF29F68BCDE052E523C287	A Truly Graceful Wipe Out
File	F176BA63B4D68E576B5BA345BEC2C7B7	A Truly Graceful Wipe Out
File	F14F2862EE2DF5D0F63A88B60C8EEE56	A Truly Graceful Wipe Out
Domain	Essadonio[.]com	A Truly Graceful Wipe Out
Domain	Ecorfan[.]org	A Truly Graceful Wipe Out
File	C92C158D7C37FEA795114FA6491FE5F145AD2F8C08776B18AE79DB811E8E36A3	A Truly Graceful Wipe Out
Domain	Atexec[.]py	A Truly Graceful Wipe Out
File	A0E9F5D64349FB13191BC781F81F42E1	A Truly Graceful Wipe Out
IPv4	92.118.36[.]199	A Truly Graceful Wipe Out
IPv4	81.19.135[.]30	A Truly Graceful Wipe Out
File	72A589DA586844D7F0818CE684948EEA	A Truly Graceful Wipe Out
File	717BEEDCD2431785A0F59D194E47970E9544FBF398D462A305F6AD9A1B1100CB	A Truly Graceful Wipe Out
IPv4	5.188.86[.]18	A Truly Graceful Wipe Out
IPv4	5.188.206[.]78	A Truly Graceful Wipe Out
IPv4	45.182.189[.]71	A Truly Graceful Wipe Out
IPv4	139.60.160[.]166	A Truly Graceful Wipe Out
File	121A1F64FFF22C4BFCEF3F11A23956ED403CDEB9BDB803F9C42763087BD6D94E	A Truly Graceful Wipe Out

 

Table 3: Truebot IOCs from May 2023 (Malicious Domains, and Associated IP addresses and URLs)
Malicious Domain	Associated IP(s)	Beacon URL
nitutdra[.]com	46.161.40[.]128
romidonionhhgtt[.]com	46.161.40.128
midnigthwaall[.]com	46.161.40[.]128
dragonetzone[.]com	46.161.40[.]128	hxxps://dragonetzone[.]com/gate_info[.]php
rprotecruuio[.]com	45.182.189[.]71
essadonio[.]com	45.182.189[.]71	hxxps://nomoresense[.]com/checkinfo[.]php
nomoresense[.]com	45.182.189[.]91	hxxps://nomoresense[.]com/checkinfo[.]php
ronoliffuion[.]com	45.182.189[.]120	hxxps://ronoliffuion[.]com/dns[.]php
bluespiredice[.]com	45.182.189[.]119
dremmfyttrred[.]com	45.182.189[.]103	hxxps://dremmfyttrred[.]com/dns[.]php
ms-online-store[.]com	45.227.253[.]102
ber6vjyb[.]com	92.118.36[.]252	hxxps://ber6vjyb[.]com/dns[.]php
jirostrogud[.]com	88.214.27[.]101	hxxps://ber6vjyb[.]com/dns[.]php
fuanshizmo[.]com	45.182.189[.]229
qweastradoc[.]com	92.118.36[.]213	hxxp://nefosferta[.]com/gate[.]php
qweastradoc[.]com	92.118.36[.]213	hxxp://nefosferta[.]com/gate[.]php
qweastradoc[.]com	92.118.36[.]213	hxxp://nefosferta[.]com/gate[.]php
hiperfdhaus[.]com	88.214.27[.]100	hxxp://nefosferta[.]com/gate[.]php
guerdofest[.]com	45.182.189[.]228	hxxp://qweastradoc[.]com/gate[.]php
nefosferta[.]com	179.60.150[.]139	hxxp://nefosferta[.]com/gate[.]php

 

Table 4: Truebot IOCs from May 2023 Continued (Malicious Domains and Associated Hashes)
Malicious Domain	MD5	SHA1	SHA256
nitutdra[.]com
romidonionhhgtt[.]com
midnigthwaall[.]com
dragonetzone[.]com	64b27d2a6a55768506a5658a31c045de	c69f080180430ebf15f984be14fb4c76471cd476	e0178ab0893a4f25c68ded11e74ad90403443e413413501d138e0b08a910471e
rprotecruuio[.]com
essadonio[.]com	9a3bad7d8516216695887acc9668cda1	a89c097138e5aab1f35b9a03900600057d907690	4862618fcf15ba4ad15df35a8dcb0bdb79647b455fea6c6937c7d050815494b0
essadonio[.]com	6164e9d297d29aa8682971259da06848	96b95edc1a917912a3181d5105fd5bfad1344de0	717beedcd2431785a0f59d194e47970e9544fbf398d462a305f6ad9a1b1100cb
nomoresense[.]com	8f924f3cbe5d8fe3ecb7293478901f1a	516051b4cab1be74d32a6c446eabac7fc354904f	6b646641c823414c2ee30ae8b91be3421e4f13fa98e2d99272956e61eecfc5a1
nomoresense[.]com	ac6a2f1eafaae9f6598390d1017dd76c	1c637c2ded5d3a13fd9b56c35acf4443f308be52	f9f649cb5de27f720d58aa44aec6d0419e3e89f453730e155067506ad3ece638
ronoliffuion[.]com	881485ac77859cf5aaa8e0d64fbafc5f	51be660a3bdaab6843676e9d3b2af8444e88bbda	36d89f0455c95f9b00a8cea843003d0b53c4e33431fe57b5e6ec14a6c2e00e99
bluespiredice[.]com
dremmfyttrred[.]com	e4a42cbda39a20134d6edcf9f03c44ed	afda13d5365b290f7cdea701d00d05b0c60916f8	47f962063b42de277cd8d22550ae47b1787a39aa6f537c5408a59b5b76ed0464
dremmfyttrred[.]com	aa949d1a7ebe5f878023c6cfb446e29b	06057d773ad04fda177f6b0f6698ddaa47f7168a	594ade1fb42e93e64afc96f13824b3dbd942a2cdbc877a7006c248a38425bbc1
dremmfyttrred[.]com	338476c2b0de4ee2f3e402f3495d0578	03916123864aa034f7ca3b9d45b2e39b5c91c502	a67df0a8b32bdc5f9d224db118b3153f66518737e702314873b673c914b2bb5c
ms-online-store[.]com
ber6vjyb[.]com	46fe07c07fd0f45ba45240ef9aae2a44	b918f97c7c6ebc9594de3c8f2d9d75ecc292d02b	c0f8aeeb2d11c6e751ee87c40ee609aceb1c1036706a5af0d3d78738b6cc4125
jirostrogud[.]com	89c8afc5bbd34f160d8a2b7218b9ca4a	16ecf30ff8c7887037a17a3eaffcb17145b69160	5cc8c9f2c9cee543ebac306951e30e63eff3ee103c62dadcd2ce43ef68bc7487
jirostrogud[.]com	5da364a8efab6370a174736705645a52	792623e143ddd49c36f6868e948febb0c9e19cd3	80b9c5ec798e7bbd71bbdfffab11653f36a7a30e51de3a72c5213eafe65965d9
fuanshizmo[.]com
qweastradoc[.]com	ee1ccb6a0e38bf95e44b73c3c46268c5	62f5a16d1ef20064dd78f5d934c84d474aca8bbe	0e3a14638456f4451fe8d76fdc04e591fba942c2f16da31857ca66293a58a4c3
qweastradoc[.]com	82d4025b84cf569ec82d21918d641540	bb32c940f9ca06e7e8533b1d315545c3294ee1a0	c042ad2947caf4449295a51f9d640d722b5a6ec6957523ebf68cddb87ef3545c
qweastradoc[.]com	dbecfe9d5421d319534e0bfa5a6ac162	9e7a2464f53ce74d840eb84077472bc29fd1ba05	c9b874d54c18e895face055eeb6faa2da7965a336d70303d0bd6047bec27a29d
qweastradoc[.]com	b7fed593e8eb3646f876367b56725e6c	44090a7858eceb28bc111e1edd2f0dc98047afb2	ff8c8c8bfba5f2ba2f8003255949678df209dbff95e16f2f3c338cfa0fd1b885
hiperfdhaus[.]com	8e2b823aac6c9e11fcabecb1d8c19adf	77ad34334a370d85ca5e77436ed99f18b185eee3	a30e1f87b78d1cd529fbe2afdd679c8241d3baab175b2f083740263911a85304
hiperfdhaus[.]com	8a94163ddf956abd0ea92d89db0034e5	abc96032071adeb6217f0a5ba1aff55dc11f5438	b95a764820e918f42b664f3c9a96141e2d7d7d228da0edf151617fabdd9166cf
guerdofest[.]com	65fb9572171b903aa31a325f550d8778	d8bd44b7a8f136e29b31226f4edf566a4223266c	d5bbcaa0c3eeea17f12a5cc3dbcaffff423d00562acb694561841bcfe984a3b7
nefosferta[.]com	d9d85bdb6a3ac60a8ba6776c661dbace	78e38e522b1765efb15d0585e13c1f1301e90788	092910024190a2521f21658be849c4ac9ae6fa4d5f2ecd44c9055cc353a26875
nefosferta[.]com	20643549f19bed9a6853810262622755	c8227dcc1cd6ecc684de8c5ea9b16e3b35f613f1	1ef8cdbd3773bd82e5be25d4ba61e5e59371c6331726842107c0f1eb7d4d1f49
nefosferta[.]com	e9299fc9b7daa0742c28bfc4b03b7b25	77360abc473dc65c8bdd73b6459b9ea8fddb6f1d	22e3f4602a258e92a0b8deb5a2bd69c67f4ac3ca67362a745178848a9da7a3cc
nefosferta[.]com	775fb391db27e299af08933917a3acda	eaaa5e68956a3a3f6113e965199f479e10ae9956	2d50b03a92445ba53ae147d0b97c494858c86a56fe037c44bc0edabb902420f7
nefosferta[.]com	f4045710c99d347fe6dfa2c0fcadde29	b7bffdbbaf817d149bbd061070a2d171449afbfc	32ae88cddeeeec255d6d9c827f6bffc7a95e9ea7b83a84a79ff793735a4b4ed7
nefosferta[.]com	587acecdb9491e0897d1067eb02e7c8d	a9eb1ac4b85d17da3a2bae5835c7e862d481c189	55d1480cd023b74f10692c689b56e7fd6cc8139fb6322762181daead55a62b9e
nefosferta[.]com	0bae65245e5423147fce079de29b6136	f24232330e6f428bfbb6b9d8154db1c4046c2fc2	6210a9f5a5e1dc27e68ecd61c092d2667609e318a95b5dade3c28f5634a89727
nefosferta[.]com	5022a85b39a75ebe2bc0411d7b058b2e	a9040ac0e9f482454e040e2a7d874ddc50e6f6ce	68a86858b4638b43d63e8e2aaec15a9ebd8fc14d460dd74463db42e59c4c6f89
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nefosferta[.]com	acac995cee8a6a75fa79eb41bdffa53f	971a00a392b99f64a3886f40b6ef991e62f0fe2f	97bae3587f1d2fd35f24eb214b9dd6eed95744bed62468d998c7ef55ff8726d4
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nefosferta[.]com	d9daaa0df32b0bb01a09e500fc7f5881	f9cb839adba612db5884e1378474996b4436c0cd	c3b3640ddf53b26f4ebd4eedf929540edb452c413ca54d0d21cc405c7263f490
nefosferta[.]com	c87fb9b9f6c343670bed605420583418	f05cf0b026b2716927dac8bcd26a2719ea328964	c6c4f690f0d15b96034b4258bdfaf797432a3ec4f73fbc920384d27903143cb0
nefosferta[.]com	2be64efd0fa7739123b26e4b70e53c5c	318fdfec4575d1530a41c80274aa8caae7b7f631	ed38c454575879c2546e5fccace0b16a701c403dfe3c3833730d23b32e41f2fe

 

Table 5: Truebot IOCs Connected to Russia, and Panama Locations
Malicious Domain	IP Addresses	Files	SHA256
Dremmfyttrred[.]com
	45.182.189[.]103
	94.142.138[.]61
	172.64.155[.]188
	104.18.32[.]68
		Update[.]exe
		Document_26_apr_2443807[.]exe
		3ujwy2rz7v[.]exe
			fe746402c74ac329231ae1b5dffa8229b509f4c15a0f5085617f14f0c1579040
droogggdhfhf[.]com		3LXJyA6Gf[.]exe	7d75244449fb5c25d8f196a43a6eb9e453652b2185392376e7d44c21bd8431e7

 

MITRE ATT&CK TACTICS AND TECHNIQUES

See Tables 6-16 for all referenced cyber threat actor tactics and techniques for enterprise environments in this advisory. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Table 6: Initial Access
Technique Title	ID	Use
Replication Through Removable Media	T1091	Cyber threat actors use removable media drives to deploy Raspberry Robin malware.
Drive-by Compromise	T1189	Cyber threat actors embed malicious links or attachments within web domains to gain initial access.
Exploit Public-Facing Application	T1190	Cyber threat actors are exploiting Netwrix vulnerability CVE-2022-31199 for initial access with follow-on capabilities of lateral movement through remote code execution.
Phishing	T1566.002	Truebot actors can send spear phishing links to gain initial access.

 

Table 7: Execution
Technique Title	ID	Use
Command and Scripting Interpreter	T1059	Cyber threat actors have been observed dropping cobalt strike beacons as a reverse shell proxy to create persistence within the compromised network. Cyber threat actors use FlawedGrace to receive PowerShell commands over a C2 channel to deploy additional tools.
Shared Modules	T1129	Cyber threat actors can deploy malicious payloads through obfuscated share modules.
User Execution: Malicious Link	T1204.001	Cyber threat actors trick users into clicking a link by making them believe they need to perform a Google Chrome software update.

 

Table 8: Persistence
Technique Title	ID	Use
Hijack Execution Flow: DLL Side-Loading	1574.002	Cyber threat actors use Raspberry Robin, among other toolsets to side-load DLLs to maintain persistence.

 

Table 9: Privilege Escalation
Technique Title	ID	Use
Boot or Logon Autostart Execution: Print Processors	T1547.012	FlawedGrace malware manipulates print spooler functions to achieve privilege escalation.

 

Table 10: Defense Evasion
Technique Title	ID	Use
Obfuscated Files or Information	T1027	Truebot uses a .JSONIP extension (e.g., IgtyXEQuCEvAM.JSONIP), to create a GUID.
Obfuscated Files or Information: Binary Padding	T1027.001	Cyber threat actors embed around one gigabyte of junk code within the malware string to evade detection protocols.
Masquerading: Masquerade File Type	T1036.008	Cyber threat actors hide Truebot malware as legitimate appearing file formats.
Process Injection	T1055	Truebot malware has the ability to load shell code after establishing a C2 connection.
Indicator Removal: File Deletion	T1070.004	Truebot malware implements self-deletion TTPs throughout its attack cycle to evade detection. Teleport exfiltration tool deletes itself after it has completed exfiltrating data to the C2 station.
Modify Registry	T1112	FlawedGrace is able to modify registry programs that control the order that documents are loaded to a print que.
Reflective Code Loading	T1620	Truebot malware has the capability to load shell code and deploy various tools to stealthily navigate an infected network.

 

Table 11: Credential Access
Technique Title	ID	Use
OS Credential Dumping: LSASS Memory	T1003.001	Cyber threat actors use cobalt strike to gain valid credentials through LSASS memory dumping.

 

Table 12: Discovery
Technique Title	ID	Use
System Network Configuration Discovery	T1016	Truebot malware scans and enumerates the affected system’s domain names.
Process Discovery	T1057	Truebot malware enumerates all running processes on the local host.
System Information Discovery	T1082	Truebot malware scans and enumerates the OS version information, and processor architecture. Truebot malware enumerates the affected system’s computer names.
System Time Discovery	T1124	Truebot has the ability to discover system time metrics, which aids in enables synchronization with the compromised system’s internal clock to facilitate scheduling tasks.
Software Discovery: Security Software Discovery	T1518.001	Truebot has the ability to discover software security protocols, which aids in defense evasion.
Debugger Evasion	T1622	Truebot malware scans the compromised environment for debugger tools and enumerates them in effort to evade network defenses.

 

Table 13: Lateral Movement
Technique Title	ID	Use
Exploitation of Remote Services	T1210	Cyber threat actors exploit CVE-2022-31199 Netwrix Auditor vulnerability and use its capabilities to move laterally within a compromised network.
Use Alternate Authentication Material: Pass the Hash	T1550.002	Cyber threat actors use cobalt strike to authenticate valid accounts
Remote Service Session Hijacking	T1563.001	Cyber threat actors use cobalt strike to hijack remote sessions using SSH and RDP hijacking methods.
Remote Service Session Hijacking: RDP Hijacking	T1563.002	Cyber threat actors use cobalt strike to hijack remote sessions using SSH and RDP hijacking methods.
Lateral Tool Transfer	T1570	Cyber threat actors deploy additional payloads to transfer toolsets and move laterally.

 

Table 14: Collection
Technique Title	ID	Use
Data from Local System	T1005	Truebot malware checks the current version of the OS and the processor architecture and compiles the information it receives. Truebot gathers and compiles compromised system’s host and domain names.
Screen Capture	T1113	Truebot malware takes snapshots of local host data, specifically processor architecture data, and sends that to a phase 2 encoded data string.

 

Table 15: Command and Control
Technique Title	ID	Use
Application Layer Protocol	T1071	Cyber threat actors use teleport exfiltration tool to blend exfiltrated data with network traffic.
Non-Application Protocol	T1095	Cyber threat actors use Teleport and FlawedGrace to send data over custom communication protocol.
Ingress Transfer Tool	T1105	Cyber threat actors deploy various ingress transfer tool payloads to move laterally and establish C2 connections.
Encrypted Channel: Asymmetric Cryptography	T1573.002	Cyber threat actors use Teleport to create an encrypted channel using AES.

 

Table 16: Exfiltration
Technique Title	ID	Use
Scheduled Transfer	T1029	Teleport limits the data it collects and syncs with outbound organizational data/network traffic.
Data Transfer Size Limits	T1030	Teleport limits the data it collects and syncs with outbound organizational data/network traffic.
Exfiltration Over C2 Channel	T1048	Cyber threat actors blend exfiltrated data with network traffic to evade detection. Cyber threat actors use the Teleport tool to exfiltrate data over a C2 protocol.

 

DETECTION METHODS

CISA and authoring organizations recommend that organizations review and implement the following detection signatures, along with: Win/malicious_confidence100% (W), Trojan:Win32/Tnega!MSR, and Trojan.Agent.Truebot.Gen, as well as YARA rules below to help detect Truebot malware.

Detection Signatures

Figure 2: Snort Signature to Detect Truebot Malware

alert tcp any any -> any any (msg:”TRUEBOT: Client HTTP Header”; sid:x; rev:1; flow:established,to_server; content:”Mozilla/112.0 (compatible|3b 20 4d 53 49 45 20 31 31 2e 30 3b 20 57 69 6e 64 6f 77 73 20 4e 54 20 31 30 2e 30 30 29|”; http_header; nocase; classtype:http-header; metadata:service http;)

 

YARA Rules

CISA developed the following YARA to aid in detecting the presence of Truebot Malware.

Figure 3: YARA Rule for Detecting Truebot Malware

rule CISA_10445155_01 : TRUEBOT downloader { meta: Author = "CISA Code & Media Analysis" Incident = "10445155" Date = "2023-05-17" Last_Modified = "20230523_1500" Actor = "n/a" Family = "TRUEBOT" Capabilities = "n/a" Malware_Type = "downloader" Tool_Type = "n/a" Description = "Detects TRUEBOT downloader samples" SHA256 = "7d75244449fb5c25d8f196a43a6eb9e453652b2185392376e7d44c21bd8431e7" strings: $s1 = { 64 72 65 6d 6d 66 79 74 74 72 72 65 64 2e 63 6f 6d } $s2 = { 4e 73 75 32 4f 64 69 77 6f 64 4f 73 32 } $s3 = { 59 69 50 75 6d 79 62 6f 73 61 57 69 57 65 78 79 } $s4 = { 72 65 70 6f 74 73 5f 65 72 72 6f 72 2e 74 78 74 } $s5 = { 4c 6b 6a 64 73 6c 66 6a 33 32 6f 69 6a 72 66 65 77 67 77 2e 6d 70 34 } $s6 = { 54 00 72 00 69 00 67 00 67 00 65 00 72 00 31 00 32 } $s7 = { 54 00 55 00 72 00 66 00 57 00 65 00 73 00 54 00 69 00 66 00 73 00 66 } condition: 5 of them }

• Additional YARA rules for detecting Truebot malware can be referenced from GitHub.[9]

INCIDENT RESPONSE

The following steps are recommended if organizations detect a Truebot malware infection and compromise:

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

MITIGATIONS

CISA and the authoring organizations recommend organizations implement the below mitigations, including mandating phishing-resistant multifactor authentication (MFA) for all staff and services.

For additional best practices, see CISA’s Cross-Sector Cybersecurity Performance Goals (CPGs). The CPGs, developed by CISA and the National Institute of Standards and Technology (NIST), are a prioritized subset of IT and OT security practices that can meaningfully reduce the likelihood and impact of known cyber risks and common TTPs. Because the CPGs are a subset of best practices, CISA and co-sealers recommend software manufacturers implement a comprehensive information security program based on a recognized framework, such as the NIST Cybersecurity Framework (CSF).

• Apply patches to CVE-2022-31199
• Update Netwrix Auditor to version 10.5

Reduce threat of malicious actors using remote access tools by:

• Implementing application controls to manage and control execution of software, including allowlisting remote access programs.
  • Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation.

See the National Security Agency’s Cybersecurity Information sheet, Enforce Signed Software Execution Policies, and additional guidance below:

• Strictly limit the use of RDP and other remote desktop services. If RDP is necessary, rigorously apply best practices, for example [CPG 2.W]:
  • Audit the network for systems using RDP.
  • Close unused RDP ports.
  • Enforce account lockouts after a specified number of attempts.
  • Apply phishing-resistant multifactor authentication (MFA).
  • Log RDP login attempts.
• Disable command-line and scripting activities and permissions [CPG 2.N].
• Restrict the use of PowerShell by using Group Policy, and only grant to specific users on a case-by-case basis. Typically, only those users or administrators who manage the network or Windows operating systems (OSs) should be permitted to use PowerShell [CPG 2.E].
• Update Windows PowerShell or PowerShell Core to the latest version and uninstall all earlier PowerShell versions. Logs from Windows PowerShell prior to version 5.0 are either non-existent or do not record enough detail to aid in enterprise monitoring and incident response activities [CPG 1.E, 2.S, 2.T].
• Enable enhanced PowerShell logging [CPG 2.T, 2.U].
  • PowerShell logs contain valuable data, including historical OS and registry interaction and possible IOCs of a cyber threat actor’s PowerShell use.
  • Ensure PowerShell instances, using the latest version, have module, script block, and transcription logging enabled (enhanced logging).
  • The two logs that record PowerShell activity are the PowerShell Windows Event Log and the PowerShell Operational Log. The authoring organizations recommend turning on these two Windows Event Logs with a retention period of at least 180 days. These logs should be checked on a regular basis to confirm whether the log data has been deleted or logging has been turned off. Set the storage size permitted for both logs to as large as possible.
• Configure the Windows Registry to require User Account Control (UAC) approval for any PsExec operations requiring administrator privileges to reduce the risk of lateral movement by PsExec.
• Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts [CPG 4.C].
• Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege (PoLP) [CPG 2.E].
• Reduce the threat of credential compromise via the following:
  • Place domain admin accounts in the protected users’ group to prevent caching of password hashes locally.
  • Implement Credential Guard for Windows 10 and Server 2016 (Refer to Microsoft: Manage Windows Defender Credential Guard for more information). For Windows Server 2012R2, enable Protected Process Light for Local Security Authority (LSA).
  • Refrain from storing plaintext credentials in scripts.
• Implement time-based access for accounts set at the admin level and higher [CPG 2.A, 2.E]. 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 (AD) 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.

In addition, CISA, FBI, MS-ISAC, and CCCS recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the impact and risk of compromise by ransomware or data extortion actors:

• Disable File and Printer sharing services. If these services are required, use strong passwords or Active Directory authentication.
• 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 (e.g., hard drive, storage device, or the cloud).
• Maintain offline backups of data and regularly maintain backup and restoration (daily or weekly at minimum). By instituting this practice, an organization minimizes the impact of disruption to business practices as they can retrieve their data [CPG 2.R]. 
• 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 15 characters [CPG 2.B].
  • Store passwords in hashed format using industry-recognized password managers.
  • Add password user “salts” to shared login credentials.
  • Avoid reusing passwords [CPG 2.C].
  • Implement multiple failed login attempt account lockouts [CPG 2.G].
  • 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 phishing-resistant multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems [CPG 2.H].
• 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 patch vulnerable software and hardware systems within 24 to 48 hours of vulnerability disclosure. Prioritize patching known exploited vulnerabilities in internet-facing systems [CPG 1.E].
• 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, restricting further lateral movement [CPG 2.F].
• Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting 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 [CPG 3.A].
• Install, regularly update, and enable real time detection for antivirus software on all hosts.
• Disable unused ports [CPG 2.V].
• Consider adding an email banner to emails received from outside your organization [CPG 2.M].
• Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure [CPG 2.K, 2.L, 2.R].

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA recommends 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. CISA recommends 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 Tables 5-13).
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.

CISA recommends 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

• NIST: NVD – CVE-2022-31199
• Stopransomware.gov (A whole-of-government approach with one central location for U.S. ransomware resources and alerts.)
• #StopRansomware Guide
• CISA: Implement Phishing-Resistant MFA
• CISA: Guide to Securing Remote Access Software
• CISA and MS-ISAC: Joint Ransomware Guide
• CISA: Cross-Sector Cybersecurity Performance Goals
• CL0P Ransomware Uses Truebot Malware for Access to Networks
• Field Offices – FBI
• NSA – Zero Trust Maturity Model

REFERENCES

[1] Bishop Fox: Netwrix Auditor Advisory
[2] Talos Intelligence: Breaking the Silence – Recent Truebot Activity
[3] The DFIR Report: Truebot Deploys Cobalt Strike and FlawedGrace
[4] MAR-10445155-1.v1 .CLEAR Truebot Activity Infects U.S. and Canada Based Networks
[5] Red Canary: Raspberry Robin Delivery Vector
[6] Microsoft: Raspberry Robin Worm Part of a Larger Ecosystem Pre-Ransomware Activity
[7] Telsy: FlawedGrace RAT
[8] VMware Security Blog: Carbon Black’s Truebot Detection
[9] GitHub: DFIR Report – Truebot Malware YARA Rule

Additional Sources

Alarming Surge in TrueBot Activity Revealed with New Delivery Vectors (thehackernews.com)
Truebot Analysis Part 1
Truebot Analysis Part 2
Truebot Analysis Part 3
Truebot Exploits Netwrix Vulnerability
TrueBot malware delivery evolves, now infects businesses in the US and elsewhere 
Malpedia-Silence Downloader
Printer spooling: what is it and how to fix it? | PaperCut

ACKNOWLEDGEMENTS

VMware’s Carbon Black contributed to this CSA.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA and authoring agencies 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, and co-sealers.

Source de l’article sur us-cert.gov