Winrs Local Command Execution

experimentalhigh
log source: windows · process_creationauthor Liran Ravich, Nasreddine Bencherchalidate 2025-10-22
01

description

What this is, in brief.

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.

02

tags

attack.lateral-movementattack.stealthattack.t1021.006attack.t1218
03

rule source (YAML)

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
04

detects techniques (2)

ATT&CK techniques this enables or maps to.

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references

External citations — patches, advisories, analysis.