PPCPROTECT11XAlexeyGorchakov

Hunt Hypothesis

This hunt hypothesis targets adversaries leveraging specific YARA signatures to identify known malicious patterns associated with the PPCPROTECT11X signature within the Azure Sentinel environment. Proactively hunting for this behavior allows the SOC team to detect early-stage threats that may not trigger high-severity alerts, ensuring comprehensive coverage against low-fidelity but potentially significant security events.

YARA Rule

rule PPCPROTECT11XAlexeyGorchakov
{
      meta:
		author="malware-lu"
strings:
		$a0 = { FF 5F 2D E9 20 00 9F E5 00 00 90 E5 18 00 8F E5 18 00 9F E5 00 00 90 E5 10 00 8F E5 01 00 A0 E3 00 00 00 EB 02 00 00 EA 04 F0 1F E5 }

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 PPCPROTECT11XAlexeyGorchakov detection rule, including suggested filters and exclusions:

• Antivirus Engine Updates via Scheduled Task

  • Scenario: The enterprise’s endpoint protection suite (e.g., Microsoft Defender Antivirus or CrowdStrike Falcon) executes a scheduled daily update task that downloads new definition signatures. This process often involves spawning temporary worker processes with similar naming conventions to the rule’s target, triggering a match during the download and installation phase.
  • Filter/Exclusion: Create an exclusion for the specific service executable path (e.g., C:\Program Files\Microsoft Defender\MsMpEng.exe or C:\ProgramData\CrowdStrike\FalconSensor\csfalcon.exe) running under the context of the “System” account during the defined maintenance window (e.g., 02:00 – 04:00 UTC).

• Software Deployment via Configuration Management Tools

  • Scenario: During a standard patching cycle, tools like Microsoft Endpoint Configuration Manager (SCCM/MECM) or Ansible Tower push application updates to workstations. The deployment agent extracts compressed payloads and launches installers that mimic the behavior patterns detected by the YARA rule, particularly when installing security-related agents or runtime libraries.
  • Filter/Exclusion: Exclude processes spawned directly by known deployment agents (e.g., ccmsetup.exe, AnsibleService.exe) where the parent process is a recognized service account (e.g., DOMAIN\PATCH-SVC). Additionally, filter out events occurring within 15 minutes of a “Software Installation” audit log entry.

• Backup Agent Scanning and Encryption Operations

  • Scenario: Enterprise backup solutions such as Veeam Backup & Replication or Rubrik run scheduled jobs to scan file systems and