VProtector11Xvcasm

Hunt Hypothesis

This detection identifies potential malicious activity associated with the VProtector11Xvcasm signature, which may indicate the presence of a specific security tool or an impersonating threat within the environment. Proactive hunting for this rule in Azure Sentinel is essential to validate whether the detected instances represent legitimate security software deployments or anomalous behavior that could signal early-stage adversary reconnaissance.

YARA Rule

rule VProtector11Xvcasm
{
      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 74 F3 75 F1 EB 24 64 FF 35 00 00 00 00 EB 12 FF 9C 74 03 75 01 E9 81 0C 24 00 01 00 00 9D 90 EB F4 64 89 25 00 00 00 00 EB E6 E8 16 00 00 00 8B 5C 24 0C 8B A3 C4 00 00 00 64 8F 05 00 00 00 00 83 C4 04 EB 14 64 FF 35 00 00 00 00 64 89 25 00 00 00 00 33 C9 99 F7 F1 E9 E8 03 00 00 00 C7 84 00 58 EB 01 E9 83 C0 07 50 C3 FF 35 E8 16 00 00 00 8B 5C 24 0C 8B A3 C4 00 00 00 64 8F 05 00 00 00 00 83 C4 04 EB 14 64 FF 35 00 00 00 00 64 89 25 00 00 00 00 33 C9 99 F7 F1 E9 E8 03 00 00 00 C7 84 00 58 EB 01 E9 83 C0 07 50 C3 }

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 VProtector11Xvcasm detection rule, along with targeted filters and exclusions:

• Scenario: Legitimate execution of the Veeam Backup & Replication service by the Windows Task Scheduler.

  • Context: The vbrsvc.exe process (Veeam) often spawns child processes or interacts with virtualization components that match the YARA signature, particularly during nightly backup windows on hypervisor hosts.
  • Filter/Exclusion: Exclude the specific file path C:\Program Files\Veeam\Backup and Replication\Tools\vbrsvc.exe and its immediate child processes from alerting when running under the SYSTEM or Veeam Backup Service account context.

• Scenario: Microsoft System Center Virtual Machine Manager (SCVMM) performing live migration or snapshot operations.

  • Context: During a “Live Migration” event, SCVMM utilizes Hyper-V integration components that may trigger the VProtector signature due to similar binary structures or embedded libraries used by both tools in virtualized environments.
  • Filter/Exclusion: Suppress alerts where the parent process is vmms.exe (SCVMM Host Service) and the event source indicates a “Migration” or “Snapshot” operation type, specifically on hosts running Windows Server 2019/2022.

• Scenario: Automated patching jobs executed by WSUS or SCCM involving virtualization agent updates.

  • Context: When Windows Update for Virtual Machines (WUfVM) pushes updates to the Veeam agent, the installer process may temporarily load modules that resemble the detection logic of the rule.
  • Filter/Exclusion: Create a time-based exclusion window (e.g., 02:00–04:00 UTC) for