VProtectorV10Evcasm

Hunt Hypothesis

This detection identifies potential malicious activity associated with the VProtector virtualization component, which may indicate an adversary leveraging custom or obfuscated code within the environment. SOC teams should proactively hunt for this signal in Azure Sentinel to validate legitimate usage and uncover early-stage anomalies that could signify a stealthy intrusion attempting to evade standard signature-based defenses.

YARA Rule

rule VProtectorV10Evcasm
{
      meta:
		author="malware-lu"
strings:
		$a0 = { EB 0A 5B 56 50 72 6F 74 65 63 74 5D 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 }

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 3-5 specific false positive scenarios for the VProtectorV10Evcasm detection rule, including specific triggers and recommended filters:

• Scenario: VMware vCenter Server Scheduled Backup Execution

  • Context: The vpxd service (VMware vCenter Server) initiates daily backup routines that spawn child processes to archive configuration data. These processes often utilize the same assembly signatures detected by the VProtector rule, mimicking the behavior of a virtualization security agent.
  • Filter/Exclusion: Exclude process paths containing C:\Program Files\VMware\vCenter Server\ and parent processes named vpxd.exe. Additionally, filter out events occurring during the configured maintenance window (e.g., 02:00–04:00 UTC).

• Scenario: CrowdStrike Falcon Sensor Real-time Scan

  • Context: The CrowdStrike Falcon sensor performs real-time scanning of virtual machine memory and disk I/O. When the sensor’s csfalcon.exe or csfalcon64.exe interacts with hypervisor components, it triggers the VProtector signature due to overlapping assembly logic in the security agent’s kernel modules.
  • Filter/Exclusion: Create an exclusion for process names matching csfalcon*.exe and csagent*.exe. If using a SIEM like Splunk or Sentinel, add a condition where Process.Name IN ('csfalcon.exe', 'csfalcon64.exe') AND Parent.Process.Name = 'services.exe'.

• Scenario: Microsoft System Center Virtual Machine Manager (SCVMM) Update Deployment

  • Context: During scheduled patching cycles, the SCVMM host service (HostAgent.exe) deploys updates to virtual machines. This deployment process involves loading specific C# assemblies that match the VProtector detection