Winrs Local Command Execution — Sigma Rule

Rule metadata and linked tags

Author: Liran Ravich, Nasreddine Bencherchali. Source status: experimental; severity: high. Source dates: 2025-10-22 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b8212e45f18402b929914eb9e16cab9ae79cb2d838e1aca98157ad3957833b9c

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: Winrs Local Command Execution
id: bcfece3d-56fe-4545-9931-3b8e92927db1
status: experimental
description: |
    Detects the execution of Winrs.exe where it is used to execute commands locally.
    Commands executed this way are launched under Winrshost.exe and can represent proxy execution used for defense evasion or lateral movement.
references:
    - https://cardinalops.com/blog/living-off-winrm-abusing-complexity-in-remote-management/
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/winrs
author: Liran Ravich, Nasreddine Bencherchali
date: 2025-10-22
tags:
    - attack.lateral-movement
    - attack.stealth
    - attack.t1021.006
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        # Note: Example of command to simulate (winrm needs to be enabled): "c:\Windows\System32\winrs.exe" calc.exe
        - Image|endswith: '\winrs.exe'
        - OriginalFileName: 'winrs.exe'
    selection_local_ip:
        CommandLine|contains|windash:
            - '/r:localhost'
            - '/r:127.0.0.1'
            - '/r:[::1]'
            - '/remote:localhost'
            - '/remote:127.0.0.1'
            - '/remote:[::1]'
    filter_main_remote:
        CommandLine|contains|windash:
            - "/r:"
            - "/remote:"
    condition: all of selection_* or (selection_img and not 1 of filter_main_*)
falsepositives:
    - Unlikely
level: high

Original YAML and metadata in JSON

False positives

• Unlikely

Source references

• https://cardinalops.com/blog/living-off-winrm-abusing-complexity-in-remote-management/
• https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/winrs