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Windows GMER.exe Execution (Rootkit Tool) via Image Path and Known Hashes

Flags execution of gmer.exe on Windows when matched by known process hashes.

FreeUnreviewedSigmahighv1
title: Windows GMER.exe Execution (Rootkit Tool) via Image Path and Known Hashes
id: f9bcfec5-716f-451c-af00-597a2c6ff705
status: test
description: This rule identifies process creation events where the executed image ends with gmer.exe and the process hash contains one of the provided known MD5/SHA1/SHA256 values. Attackers may use GMER to assess or manipulate system components in support of stealthy/rootkit activity, so tool execution is a high-signal indicator. It relies on Windows process creation telemetry that includes the Image path (or image name) and cryptographic hash fields.
references:
  - http://www.gmer.net/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_hktl_gmer.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-10-05
modified: 2024-11-23
tags:
  - attack.stealth
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    Image|endswith: \gmer.exe
  selection_sysmon_hash:
    Hashes|contains:
      - MD5=E9DC058440D321AA17D0600B3CA0AB04
      - SHA1=539C228B6B332F5AA523E5CE358C16647D8BBE57
      - SHA256=E8A3E804A96C716A3E9B69195DB6FFB0D33E2433AF871E4D4E1EAB3097237173
  condition: 1 of selection_*
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: 9082ff1f-88ab-4678-a3cc-5bcff99fc74d
    type: derived

What it detects

This rule identifies process creation events where the executed image ends with gmer.exe and the process hash contains one of the provided known MD5/SHA1/SHA256 values. Attackers may use GMER to assess or manipulate system components in support of stealthy/rootkit activity, so tool execution is a high-signal indicator. It relies on Windows process creation telemetry that includes the Image path (or image name) and cryptographic hash fields.

Known false positives

  • Unlikely

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.