Auto-generated rule on file aolipsniffer.exe

Hunt Hypothesis

This hunt hypothesis targets potential reconnaissance or initial access activities where adversaries execute the AOL IP Sniffer utility to map network topology and identify internal hosts. Proactively hunting for this behavior in Azure Sentinel is essential because legitimate use of aolipsniffer.exe can be masked by threat actors to establish a foothold, making early detection critical before lateral movement occurs.

YARA Rule

rule aolipsniffer {
	meta:
		description = "Auto-generated rule on file aolipsniffer.exe"
		author = "yarGen Yara Rule Generator by Florian Roth"
		hash = "51565754ea43d2d57b712d9f0a3e62b8"
	strings:
		$s0 = "C:\\Program Files\\Microsoft Visual Studio\\VB98\\VB6.OLB"
		$s1 = "dwGetAddressForObject"
		$s2 = "Color Transfer Settings"
		$s3 = "FX Global Lighting Angle"
		$s4 = "Version compatibility info"
		$s5 = "New Windows Thumbnail"
		$s6 = "Layer ID Generator Base"
		$s7 = "Color Halftone Settings"
		$s8 = "C:\\WINDOWS\\SYSTEM\\MSWINSCK.oca"
	condition:
		all of them
}

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 9 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the aolipsniffer.exe detection rule in an enterprise environment, along with suggested filters:

• Scenario: Scheduled Antivirus Network Scan

  • Context: The AOL Security Suite (often bundled in legacy Windows environments or specific corporate VDI setups) triggers a network interface sniffer process (aolipsniffer.exe) during its daily scheduled “Deep Network Inspection” job. This occurs automatically at 02:00 AM via the Task Scheduler, scanning active ports and listening services without user interaction.
  • Suggested Filter: Exclude alerts where the parent process is TaskScheduler (or specifically the task name containing “AOL Security Daily Scan”) AND the execution time falls within the maintenance window of 01:30 AM to 04:00 AM.

• Scenario: Endpoint Protection Agent Update Deployment

  • Context: During a mass deployment of security policy updates via Microsoft Endpoint Configuration Manager (SCCM) or Intune, the aolipsniffer.exe process is spawned as part of the agent’s initialization routine to verify network connectivity and firewall rule integrity before applying new signatures. This often triggers when users log in after an overnight patch cycle.
  • Suggested Filter: Create a suppression rule for events where the command line arguments contain keywords like --update-check, --verify-policy, or --init-network AND the user context is a service account (e.g., DOMAIN\SCCM-Service or SYSTEM).

• Scenario: Legacy Application Integration with CRM

  • Context: A specific legacy Customer Relationship Management (CRM) module installed on sales laptops utilizes aolipsniffer.exe as a background helper to monitor real-time data synchronization between the local client and the cloud server. This process runs persistently whenever the “Sales Sync