VProtectorV11vcasm

Hunt Hypothesis

This detection identifies the presence of the VProtector antivirus engine within the environment by matching specific YARA signatures against executable files in Azure Sentinel. Proactively hunting for this signature allows the SOC team to validate legitimate security tool coverage and distinguish known benign processes from potential false positives or unauthorized software installations that may mimic established protection mechanisms.

YARA Rule

rule VProtectorV11vcasm
{
      meta:
		author="malware-lu"
strings:
		$a0 = { B8 1A ED 41 00 B9 EC EB 41 00 50 51 E8 74 00 00 00 E8 51 6A 00 00 58 83 E8 10 B9 B3 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

False Positive Scenarios for Rule: VProtectorV11vcasm

• Scenario 1: Scheduled Antivirus Engine Updates

  • Context: The enterprise’s endpoint protection suite (e.g., Symantec Endpoint Protection or CrowdStrike Falcon) performs a nightly scheduled task to download and apply the latest signature definitions. This process often involves extracting compressed archives containing CASM (Cloud Application Security Module) components that match the YARA rule’s structural signatures.
  • Suggested Filter: Create an exclusion based on the specific service account used for updates (e.g., NT SERVICE\SymantecEndpointProtection or SYSTEM) and restrict the detection to non-business hours (01:00 – 05:00 local time). Additionally, exclude file paths containing \Program Files\Common Files\Symantec Shared\Data.

• Scenario 2: Microsoft Office Add-in Deployment via Group Policy

  • Context: During a monthly patch cycle, the IT team deploys new versions of the Microsoft Office VBA Add-ins or Visio plugins using Microsoft Endpoint Configuration Manager (MECM/SCCM). The installation process extracts .cab or .msi payloads that include CASM-related binaries which trigger the rule.
  • Suggested Filter: Exclude processes spawned by ccmsetup.exe, msiexec.exe, and wusa.exe when running under the context of the domain admin account (DOMAIN\SCCM-Admin). Add a path exclusion for files located in %ProgramFiles%\Microsoft Office\root\Office16\Addins.

• Scenario 3: Database Backup and Recovery Operations

  • Context: A nightly backup job managed by Veeam Backup & Replication or Commvault archives critical SQL Server databases. The backup engine utilizes a