Description of Campaign
A variant of the AvosLocker ransomware family was discovered disabling anti-virus solutions and detection evasion by using a legitimate Avast Anti-Rootkit Driver file. The malware also used an Nmap NSE script to scan endpoints vulnerable to the Log4shell Apache Log4j remote code execution vulnerability.
The AvosLocker campaign also downloaded and used Netscan, Mimikatz, Impacket, PDQ, AnyDesk, and XenArmor to carry out the infection process.
Our ATR Team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports. This campaign was researched by Trend Micro 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.
This Knowledge Base article discusses a specific threat that's being tracked. The list of IOCs will change over time; check MVISION Insights for the latest IOCs.
Campaign IOC
| Type |
Value |
| SHA256 |
14F0C4CE32821A7D25EA5E016EA26067D6615E3336C3BAA854EA37A290A462A8 |
| SHA256 |
912018AB3C6B16B39EE84F17745FF0C80A33CEE241013EC35D0281E40C0658D9 |
| SHA256 |
E81A8F8AD804C4D83869D7806A303FF04F31CCE376C5DF8AADA2E9DB2C1EEB98 |
Minimum Content Versions
| Content Type |
Version |
| V2 DAT (VirusScan Enterprise) |
9555 |
| V3 DAT (Endpoint Security) |
4006 |
Detection Summary
| IOC |
Scanner |
Detection |
| 14F0C4CE32821A7D25EA5E016EA26067D6615E3336C3BAA854EA37A290A462A8 |
AVEngine V2 |
HTool-WMIExec |
| AVEngine V3 |
HTool-WMIExec |
| JTI (ATP Rules) |
JTI/Suspect.196612!47e001253af2 |
| RP Static |
- |
| RP Dynamic |
- |
| IOC |
Scanner |
Detection |
| 912018AB3C6B16B39EE84F17745FF0C80A33CEE241013EC35D0281E40C0658D9 |
AVEngine V2 |
HTool-MimiKatz!BB8BDB3E8C92 |
| AVEngine V3 |
HTool-MimiKatz!BB8BDB3E8C92 |
| JTI (ATP Rules) |
JTI/Suspect.196612!bb8bdb3e8c92 |
| RP Static |
- |
| RP Dynamic |
- |
| IOC |
Scanner |
Detection |
| E81A8F8AD804C4D83869D7806A303FF04F31CCE376C5DF8AADA2E9DB2C1EEB98 |
AVEngine V2 |
HTool-Mimikatz |
| AVEngine V3 |
HTool-Mimikatz |
| JTI (ATP Rules) |
JTI/Suspect.196612!6c9ad4e67032 |
| RP Static |
- |
| RP Dynamic |
- |
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: 6070 Hidden PowerShell Detected
Rule ID: 6083 PowerShell Command Restriction - NonInteractive
Rule ID: 6081 PowerShell Command Restriction - NoProfile
Rule ID: 6135 Unmanaged PowerShell Detected
Rule ID: 6113 T1055 - Fileless Threat: Reflective Self Injection
Endpoint Security - Access Protection Rules:
Executing Mimikatz malware
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: 6010 Generic Application Hooking Protection
Rule ID: 6011 Generic Application Invocation Protection
Rule ID: 1020 Windows Agent Shielding - File Access
Rule ID: 1148 CMD Tool Access by a Network Aware Application
