VProtectorV11Avcasm

Hunt Hypothesis

This detection identifies the presence of the VProtector antivirus component (version 11) on endpoints, signaling potential security software installation or updates that could impact system performance and visibility. A proactive hunt is recommended to verify the legitimacy of this process across the Azure Sentinel environment, ensuring it aligns with known baseline configurations and does not interfere with other critical security operations.

YARA Rule

rule VProtectorV11Avcasm
{
      meta:
		author="malware-lu"
strings:
		$a0 = { EB 0B 5B 56 50 72 6F 74 65 63 74 5D 00 E8 24 00 00 00 8B 44 24 04 8B 00 3D 04 00 00 80 75 08 8B 64 24 08 EB 04 58 EB 0C E9 64 8F 05 00 00 00 00 }

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 4 specific false positive scenarios for the VProtectorV11Avcasm detection rule, including suggested filters and exclusions:

• Scenario: Scheduled Antivirus Scans by VPROTector Agent

  • Context: The VProtector agent itself runs scheduled full or quick scans during business hours (e.g., 09:00–17:00), triggering the YARA rule as it loads its own signature database and heuristic modules. This is a common self-detection loop where the security tool detects its own execution components.
  • Filter/Exclusion: Create an exclusion for the VProtector service executable path (e.g., C:\Program Files\VProtector\bin\VProtectorService.exe) and exclude processes spawned by this parent PID during scheduled maintenance windows.

• Scenario: Deployment of Updates via Microsoft Endpoint Configuration Manager (SCCM)

  • Context: During a patch Tuesday cycle, the SCCM client (ccmexec.exe) pushes a new VProtector definition update or engine version to endpoints. The installation process involves unpacking and executing assembly scripts that match the Avcasm signature pattern within the YARA rule.
  • Filter/Exclusion: Exclude alerts where the parent process is ccmexec.exe (Microsoft Configuration Manager) and the file path resides in the temporary deployment folder (C:\Windows\CCMCache\).

• Scenario: Automated Backup Jobs by Veeam or Commvault

  • Context: Enterprise backup solutions like Veeam Agent or Commvault often utilize VProtector as a plug-in for real-time file protection during backup operations. The backup engine invokes the Avcasm module to scan files before archiving, generating legitimate alerts that mimic potential threats.
  • Filter/Exclusion: Implement a