CommentCrew-threat-apt1

Hunt Hypothesis

CommentCrew-threat-apt1 detects potential adversary behavior involving suspicious comment-based PowerShell scripts that may be used for initial access or command and control. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate early-stage compromise attempts by threat actors leveraging script-based persistence.

YARA Rule

rule AURIGA_APT1
{

    meta:
        author = "AlienVault Labs"
        info = "CommentCrew-threat-apt1"
        
    strings:
        $s1 = "superhard corp." wide ascii
        $s2 = "microsoft corp." wide ascii
        $s3 = "[Insert]" wide ascii
        $s4 = "[Delete]" wide ascii
        $s5 = "[End]" wide ascii
        $s6 = "!(*@)(!@KEY" wide ascii
        $s7 = "!(*@)(!@SID=" wide ascii

    condition:
        all of them
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 7 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Scenario: Scheduled system backup using Veeam Backup & Replication
  Filter/Exclusion: process.name != "vbm" AND process.name != "vbackup"

• Scenario: Admin performing a Windows Update via Group Policy
  Filter/Exclusion: process.name != "wusa.exe" AND process.name != "gpupdate.exe"

• Scenario: Database maintenance task using SQL Server Agent Job
  Filter/Exclusion: process.name != "sqlservr.exe" AND process.name != "sqlagent.exe"

• Scenario: User running a PowerShell script for log rotation or file cleanup
  Filter/Exclusion: process.name != "powershell.exe" OR process.args NOT LIKE "*logrotate*" AND process.args NOT LIKE "*cleanup*"

• Scenario: IT staff using Ansible to deploy configuration changes
  Filter/Exclusion: process.name != "ansible" AND process.name != "ansible-playbook"