Windows Sysmon Configuration Update via Sysmon64 Command-Line

Flags execution of Sysmon binaries with '-c', indicating a Sysmon configuration update attempt.

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windows-sysmon-configuration-update-via-sysmon64-command-line-87911521

title: Windows Sysmon Configuration Update via Sysmon64 Command-Line
id: 810bf020-4a45-432d-acf3-017b06743655
status: test
description: This rule matches process creation events where Sysmon64/Sysmon64a/Sysmon is launched with a command line containing the '-c' argument used for configuration updates. Attackers can abuse configuration changes to weaken or alter monitoring while leaving the Sysmon service running. The detection relies on Windows process creation telemetry, including the image path, process description, and command line content.
references:
  - https://learn.microsoft.com/en-us/sysinternals/downloads/sysmon
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_sysinternals_sysmon_config_update.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2023-03-09
modified: 2026-06-29
tags:
  - attack.defense-impairment
  - attack.t1685
logsource:
  category: process_creation
  product: windows
detection:
  selection_pe:
    - Image|endswith:
        - \Sysmon64.exe
        - \Sysmon64a.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
license: DRL-1.1
related:
  - id: 87911521-7098-470b-a459-9a57fc80bdfd
    type: derived

What it detects

This rule matches process creation events where Sysmon64/Sysmon64a/Sysmon is launched with a command line containing the '-c' argument used for configuration updates. Attackers can abuse configuration changes to weaken or alter monitoring while leaving the Sysmon service running. The detection relies on Windows process creation telemetry, including the image path, process description, and command line content.

Known false positives

Legitimate administrators might use this command to update Sysmon configuration.

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