IndiaBravo PapaAlfa

Hunt Hypothesis

This detection identifies potential initial access or execution activities associated with the IndiaBravo and PapaAlfa threat actors by leveraging specific YARA signatures within endpoint telemetry. Proactively hunting for these indicators in Azure Sentinel is critical to establish a baseline of known adversary behavior before escalating low-severity signals into confirmed incidents, thereby reducing mean time to detect early-stage intrusions.

YARA Rule

rule IndiaBravo_PapaAlfa
{
	meta:
		copyright = "2015 Novetta Solutions"
		author = "Novetta Threat Research & Interdiction Group - trig@novetta.com"

	strings:
		$ = "pmsconfig.msi" wide
		$ = "scvrit001.bat"
	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
• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the IndiaBravo PapaAlfa detection rule in an enterprise environment, along with recommended filters:

• Microsoft Endpoint Configuration Manager (MECM/SCCM) Software Updates Deployment

  • Scenario: The SCCM agent (ccmexec.exe) or the Windows Update service initiates a scheduled task to download and install critical security patches. This process often involves spawning temporary worker processes that execute scripts with signatures matching the IndiaBravo_PapaAlfa logic, specifically when deploying updates to the “India” region cluster.
  • Filter/Exclusion: Exclude alerts where the parent process is ccmexec.exe or usocoreworker.exe, and the execution path resides within C:\Windows\CCM\ or C:\Program Files (x86)\Microsoft Intune Management Extension.

• CrowdStrike Falcon Sensor Real-Time Scan

  • Scenario: During peak business hours, the CrowdStrike sensor performs an on-access scan of user directories. The scanner’s heuristic engine may spawn a child process to analyze large archives (e.g., .zip or .tar.gz files) containing legitimate corporate documents, triggering the YARA rule due to specific file header patterns common in enterprise data sets.
  • Filter/Exclusion: Create an exclusion for processes with the executable name csfalcon.exe or csagent.exe, specifically filtering out events where the file being scanned has a .zip, .pdf, or .docx extension and originates from user home directories (e.g., C:\Users\*\Documents).

• Tenable Nessus Vulnerability Scanning Agent

  • Scenario: The Tenable agent runs a scheduled vulnerability assessment job. When checking for outdated software versions, it launches a temporary analysis utility that reads registry keys and local file manifests. This