Trellix Insights: Tracing the Chaos Ransomware Family Tree
Technical Articles ID:
KB95837
Last Modified: 2022-08-22 10:44:39 Etc/GMT
Last Modified: 2022-08-22 10:44:39 Etc/GMT
Environment
IMPORTANT: This Knowledge Base article discusses a specific threat that is being automatically tracked by Trellix Insights technology. The content is intended for use by Trellix Insights users, but is provided for general knowledge to all customers. Contact us for more information about Trellix Insights.
Summary
Description of Campaign
The Chaos ransomware family first hit the threat landscape in 2021 and continues to be updated on a regular basis. The first iterations of the malware were compiled in .NET and acted more like a wiper instead of ransomware.
The malware couldn't encrypt large files, causing the files to be unrecoverable. Later versions of the malware stole and posted sensitive data to get victims to pay. The latest version of the ransomware added the ability to check the system's language and doesn't encrypt devices in certain countries.
Our ATR team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports. This campaign was researched by BlackBerry and shared publicly.
How to use this article:
This Knowledge Base article discusses a specific threat that's being tracked. The list of IOCs will change over time; check Trellix Insights for the latest IOCs.
Campaign IOC
Minimum Content Versions
Detection Summary
Minimum set of Manual Rules to improve protection to block this campaign:
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
Endpoint Security - Advanced Threat Protection:Rule ID: 239 Identify suspicious command parameter execution
Rule ID: 4 Use GTI file reputation to identify trusted or malicious files
Host Intrusion Prevention:Rule ID: 6070 Hidden PowerShell Detected
Rule ID: 6081 PowerShell Command Restriction - NoProfile
Rule ID: 6113 T1055 - Fileless Threat: Reflective Self Injection
Rule ID: 6083 PowerShell Command Restriction - NonInteractive
Aggressive set of Manual Rules to improve protection to block this campaign:
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
VirusScan Enterprise - Access Protection Rules:Prevent creation of new executable files in the Windows folder
Host Intrusion Prevention:Rule ID: 344 T1547 - New Startup Program Creation
Rule ID: 6010 Generic Application Hooking Protection
Rule ID: 1148 CMD Tool Access by a Network Aware Application
Rule ID: 6011 Generic Application Invocation Protection
Rule ID: 1020 Windows Agent Shielding - File Access
The Chaos ransomware family first hit the threat landscape in 2021 and continues to be updated on a regular basis. The first iterations of the malware were compiled in .NET and acted more like a wiper instead of ransomware.
The malware couldn't encrypt large files, causing the files to be unrecoverable. Later versions of the malware stole and posted sensitive data to get victims to pay. The latest version of the ransomware added the ability to check the system's language and doesn't encrypt devices in certain countries.
Our ATR team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports. This campaign was researched by BlackBerry and shared publicly.
How to use this article:
- If a Threat Hunting table has been created, use the rules contained to search for malware related to this campaign.
- Review the product detection table and confirm that your environment is at least on the specified content version.
To download the latest content versions, go to the Security Updates page. - Scroll down and review the "Product Countermeasures" section of this article. Consider implementing them if they are not already in place.
- Review
KB91836 - Countermeasures for entry vector threats . - Review KB87843 - Dynamic Application Containment rules and best practices.
- Review KB82925 - Identify what rule corresponds to an Adaptive Threat Protection and Threat Intelligence Exchange event.
rule Mal_Win32_ChaosRansomware_2022 { meta: description = "Detects Ransomware Built by Chaos Ransomware Builder" author = "BlackBerry Threat Research" date = "2022-05-10" license = "This Yara rule is provided under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0) and open to any user or organization, as long as you use it under this license and ensure originator credit in any derivative to The BlackBerry Research & Intelligence Team" strings: //Ransom References $x1 = "Encrypt" ascii wide $x2 = "(?:[13]{1.EN_US}[a-km-zA-HJ-NP-Z1-9]{26,33}|bc1[a-z0-9]{39,59})" ascii wide $x3 = "read" ascii wide //Ransom Hex $r1 = { 20 76 69 72 75 73 } $r2 = { 72 00 61 00 6e 00 73 00 6f 00 6d 00 77 00 61 00 72 00 65 } //Shadow Copy Delete $z0 = "deleteShadowCopies" ascii wide $z1 = "shadowcopy" ascii wide condition: //PE File uint16(0) == 0x5a4d and // Must be less than filesize < 35KB and // Must have exact import hash pe.imphash() == "f34d5f2d4577ed6d9ceec516c1f5a744" and //Number of sections pe.number_of_sections == 3 and //These Strings ((all of ($x*)) and (1 of ($r*)) and (1 of ($z*))) } |
|
rule Mal_Win32_Onyx_Strain_Chaos_Ransomware_2022 { meta: description = "Detects Onyx Ransomware build off of Chaos Builder v4" author = "BlackBerry Threat Research" date = "2022-05-10" license = "This Yara rule is provided under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0) and open to any user or organization, as long as you use it under this license and ensure originator credit in any derivative to The BlackBerry Research & Intelligence Team" strings: $s1 = "(?:[13]{1.EN_US}[a-km-zA-HJ-NP-Z1-9]{26,33}|bc1[a-z0-9]{39,59})" wide $s2 = "All of your files are currently encrypted by ONYX strain." wide $s3 = "Inform your supervisors and stay calm!" wide condition: //PE File uint16(0) == 0x5a4d and //Directories pe.data_directories[pe.IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR].size != 0 and //All strings all of ($s*) } |
|
rule Mal_Win32_Chaos_Builder_Ransomware_2022 { meta: description = "Detects Chaos Ransomware Builder" author = "BlackBerry Threat Research" date = "2022-05-10" license = "This Yara rule is provided under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0) and open to any user or organization, as long as you use it under this license and ensure originator credit in any derivative to The BlackBerry Research & Intelligence Team" strings: $s0 = "1qw0ll8p9m8uezhqhyd" ascii wide $s1 = "Chaos Ransomware Builder" ascii wide $s2 = "payloadFutureName" ascii wide $s3 = "read_it.txt" ascii wide $s4 = "encryptedFileExtension" ascii wide $x0 = "1098576" ascii wide $x1 = "2197152" ascii wide condition: //PE File uint16(0) == 0x5a4d and //All strings ((all of ($s*)) and (1 of ($x*))) } |
This Knowledge Base article discusses a specific threat that's being tracked. The list of IOCs will change over time; check Trellix Insights for the latest IOCs.
Campaign IOC
Type | Value |
Minimum Content Versions
Content Type | Version |
Detection Summary
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
Minimum set of Manual Rules to improve protection to block this campaign:
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
Endpoint Security - Advanced Threat Protection:
Rule ID: 4 Use GTI file reputation to identify trusted or malicious files
Host Intrusion Prevention:
Rule ID: 6081 PowerShell Command Restriction - NoProfile
Rule ID: 6113 T1055 - Fileless Threat: Reflective Self Injection
Rule ID: 6083 PowerShell Command Restriction - NonInteractive
Aggressive set of Manual Rules to improve protection to block this campaign:
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
VirusScan Enterprise - Access Protection Rules:
Host Intrusion Prevention:
Rule ID: 6010 Generic Application Hooking Protection
Rule ID: 1148 CMD Tool Access by a Network Aware Application
Rule ID: 6011 Generic Application Invocation Protection
Rule ID: 1020 Windows Agent Shielding - File Access