PseudoSigner01ACProtect109Anorganix

Hunt Hypothesis

This detection identifies potential obfuscated malware utilizing ACProtect v10.9 and Anorganix signatures to evade standard signature-based defenses by masking executable characteristics. A proactive hunt is essential in Azure Sentinel to uncover stealthy threats that may bypass initial scanning layers, ensuring early identification of sophisticated fileless or packed attacks before they establish persistence.

YARA Rule

rule PseudoSigner01ACProtect109Anorganix
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 EB 02 00 00 90 90 90 04 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 }

condition:
		$a0 at pe.entry_point
}

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 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 5 specific false positive scenarios for the PseudoSigner01ACProtect109Anorganix detection rule, including suggested filters and exclusions:

• Scenario: Deployment of AC-Protected Enterprise Applications via SCCM/Intune

  • Context: System administrators frequently deploy line-of-business (LOB) applications or third-party utilities that utilize the “ACProtect” packing engine for obfuscation. When these tools are installed or updated via Microsoft Endpoint Configuration Manager (SCCM) or Intune, the executable often triggers this rule due to its packed signature structure matching the YARA logic.
  • Suggested Filter/Exclusion: Create a whitelist entry based on the specific SHA-256 hash of the known-good installer package. Alternatively, exclude the detection for processes running under the System or Network Service account when initiated by the ccmsetup.exe (SCCM) or IntuneAgent service paths.

• Scenario: Scheduled Antivirus Signature Updates

  • Context: Many enterprise antivirus solutions (e.g., CrowdStrike Falcon, Symantec Endpoint Protection, or McAfee) utilize ACProtect to pack their update agents or signature definition files. During the scheduled daily update window (typically 02:00–04:00), the extraction and execution of these packed components can trigger a match on this rule.
  • Suggested Filter/Exclusion: Implement a time-based exclusion for the detection logic between 01:30 and 05:00 UTC, or add an exclusion path for known AV vendor directories (e.g., C:\Program Files\CrowdStrike\ or C:\ProgramData\McAfee\).

• Scenario: Execution of Internal Reporting Tools with Obfuscated Binaries

  • Context: Finance and HR departments often use