Potential Lateral Movement via Windows Remote Shell

Hunt Hypothesis

Detects a child process spawned by ‘winrshost.exe’, which suggests remote command execution through Windows Remote Shell (WinRs) and may indicate potential lateral movement activity.

Detection Rule

Sigma (Original)

title: Potential Lateral Movement via Windows Remote Shell
id: 79df3f68-dccb-48e9-9171-b75cbc37c51d
status: experimental
description: |
    Detects a child process spawned by 'winrshost.exe', which suggests remote command execution through Windows Remote Shell (WinRs) and may indicate potential lateral movement activity.
references:
    - https://cardinalops.com/blog/living-off-winrm-abusing-complexity-in-remote-management/
    - https://www.ired.team/offensive-security/lateral-movement/winrs-for-lateral-movement
author: Liran Ravich
date: 2025-10-22
tags:
    - attack.lateral-movement
    - attack.t1021.006
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        # Note: Example of command to simulate (winrm needs to be enabled): "c:\Windows\System32\winrs.exe" powershell
        ParentImage|endswith: '\winrshost.exe'
    filter_main_conhost:
        Image: 'C:\Windows\System32\conhost.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate use of WinRM within the organization
level: medium

KQL (Azure Sentinel)

imProcessCreate
| where (ParentProcessName endswith "\\winrshost.exe" or ActingProcessName endswith "\\winrshost.exe") and (not(TargetProcessName =~ "C:\\Windows\\System32\\conhost.exe"))

Required Data Sources

False Positive Guidance

• Legitimate use of WinRM within the organization

MITRE ATT&CK Context

• Tactic: Lateral Movement
• Technique: T1021.006 — T1021.006

References

• https://cardinalops.com/blog/living-off-winrm-abusing-complexity-in-remote-management/
• https://www.ired.team/offensive-security/lateral-movement/winrs-for-lateral-movement
• SigmaHQ Rule