Sysmon Configuration Update — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-03-09 / 2024-03-13.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: c4488d303d6191a77aca8795824f95764a4dacbf8a89254785e95893a6142fb8

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Sysmon Configuration Update
id: 87911521-7098-470b-a459-9a57fc80bdfd
status: test
description: Detects updates to Sysmon's configuration. Attackers might update or replace the Sysmon configuration with a bare bone one to avoid monitoring without shutting down the service completely
references:
    - https://learn.microsoft.com/en-us/sysinternals/downloads/sysmon
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-03-09
modified: 2024-03-13
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: process_creation
    product: windows
detection:
    selection_pe:
        - Image|endswith:
              - \Sysmon64.exe
              - \Sysmon.exe
        - Description: 'System activity monitor'
    selection_cli:
        CommandLine|contains|windash: '-c'
    condition: all of selection_*
falsepositives:
    - Legitimate administrators might use this command to update Sysmon configuration.
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate administrators might use this command to update Sysmon configuration.

Source references

• https://learn.microsoft.com/en-us/sysinternals/downloads/sysmon