Auto-generated rule on file scanarator.exe

Hunt Hypothesis

This detection identifies the execution of scanarator.exe, a behavior often associated with legitimate scanning tools but potentially indicative of an adversary leveraging this process for initial reconnaissance or lateral movement within the environment. Proactive hunting is essential to validate whether these executions align with known administrative activities or represent anomalous usage patterns that could signal early-stage compromise attempts in Azure Sentinel.

YARA Rule

rule scanarator {
	meta:
		description = "Auto-generated rule on file scanarator.exe"
		author = "yarGen Yara Rule Generator by Florian Roth"
		hash = "848bd5a518e0b6c05bd29aceb8536c46"
	strings:
		$s4 = "GET /scripts/..%c0%af../winnt/system32/cmd.exe?/c+dir HTTP/1.0"
	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 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the scanarator.exe detection rule, including suggested filters and exclusions:

• Scenario: Scheduled Antivirus Database Update

  • Context: The enterprise’s endpoint protection suite (e.g., Microsoft Defender or CrowdStrike) runs a nightly scheduled task to download and install new virus definition signatures. This process often spawns scanarator.exe as a helper utility to scan the newly downloaded signature files before deployment.
  • Filter/Exclusion: Create an exclusion based on the Parent Process. Filter out alerts where the parent process is MsMpEng.exe (Microsoft Defender) or Csfalcon.exe (CrowdStrike), specifically during the maintenance window of 02:00 – 04:00 UTC.

• Scenario: Deployment via Configuration Management Tool

  • Context: During a patch Tuesday deployment, the IT team uses Microsoft Endpoint Configuration Manager (MECM/SCCM) or Ansible to push security policies. The scanarator.exe binary is executed as part of the post-installation verification script on the client machines to ensure local file integrity.
  • Filter/Exclusion: Exclude alerts originating from specific Service Accounts. Add a rule exclusion for processes launched by SCCMClientAgent$, Ansible-Runner, or any account with the prefix svc-deploy- running on known management servers (e.g., SRV-MGMT-01).

• Scenario: Automated Compliance Audit Script

  • Context: A monthly compliance audit is triggered by a custom PowerShell script located in C:\Scripts\Compliance. This script invokes scanarator.exe to perform a deep scan of the “Financial Reports” shared folder (\\FileServer\Financial) to verify file hashes against a baseline.