LauncherGeneratorv103

Hunt Hypothesis

This detection identifies the execution of a known launcher generator tool that may be utilized by adversaries to stage payloads or facilitate lateral movement within the environment. Proactive hunting for this activity in Azure Sentinel is essential to distinguish legitimate administrative usage from potential early-stage threat actor behavior that could precede more significant compromise events.

YARA Rule

rule LauncherGeneratorv103
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 68 00 20 40 00 68 10 20 40 00 6A 00 6A 00 6A 20 6A 00 6A 00 6A 00 68 F0 22 40 00 6A 00 E8 93 00 00 00 85 C0 0F 84 7E 00 00 00 B8 00 00 00 00 3B 05 68 20 40 00 74 13 6A ?? 68 60 23 40 00 68 20 23 40 00 6A 00 E8 83 00 00 00 A1 58 20 40 00 3B 05 6C 20 40 00 }

condition:
		$a0
}

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 LauncherGeneratorv103 detection rule, including suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Microsoft Office Click-to-Run (C2R) Self-Repair or Update Launchers

  • Context: The Office C2R service frequently generates temporary launcher executables in the %ProgramFiles%\Microsoft Office\root\Office16 directory to initiate background updates, self-repairs, or feature installations. These processes often match the signature of a generic generator tool.
  • Filter/Exclusion: Exclude file paths containing C:\Program Files\Microsoft Office\root\Office*\* where the parent process is officeclicktorun.exe or setup.exe. Additionally, filter out events where the command line contains arguments like /configure, /repair, or update.

• Scenario: Endpoint Protection (e.g., CrowdStrike or Carbon Black) Policy Push Agents

  • Context: Security agents often spawn a “launcher” process to distribute new policy definitions, scan definitions, or agent updates. For instance, CrowdStrike’s Falcon Sensor uses a generator module to launch the csfalcon update service, which can be misidentified as a third-party launcher generator.
  • Filter/Exclusion: Create an exclusion for processes running under the user context of the specific security vendor (e.g., CrowdStrike, Carbon Black) where the file path resides in C:\Program Files\CrowdStrike\ or C:\ProgramData\Carbon Black. Filter based on the parent process name being the main sensor daemon (e.g., csfalcon.exe).

• Scenario: Scheduled PowerShell Deployment Scripts via Task Scheduler

  • Context: IT Operations teams often use scheduled tasks to deploy software updates or configuration scripts. These tasks frequently invoke a generic