Windows process creation: child process spawned by winrshost.exe

Flags Windows process children of winrshost.exe that may indicate WinRS-driven remote command execution.

FreeReviewedSigma · Medium · v1

Product: windows
Category: process_creation
Author: Liran Ravich (SigmaHQ), DRL 1.1
Published: 2025-10-22
Updated: 2026-07-30

ATT&CK techniques

Lateral Movement

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
- T1021.006Windows Remote Management
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies when a process is created as a child of winrshost.exe on Windows, indicating remote command execution via Windows Remote Shell (WinRS). Such activity can be used to run commands on additional hosts and may support lateral movement. It relies on Windows process creation telemetry, matching the parent executable name and excluding cases involving conhost.exe as the spawned image.

Reporting behind it

Related detections9 linkedT1021.006 — drag to rearrange

Suspicious WinRM Compatibility HTTPS Listener Enabled via winrm.vbs

Malicious Invoke-WMIExec Lateral Movement Download and Execute (via ps_script)

Windows Winrs.exe Local Command Execution via localhost/loopback

Windows PowerShell: Invoke-Command targeting -ComputerName via script block

Windows PowerShell script enabling WinRM via Enable-PSRemoting

Windows HackTool Activity: Evil-WinRM Ruby Process with -i, -u, -p Arguments

Zeek HTTP POST to /wsman without Authorization — Possible OMIGOD unauthenticated RCE (CVE-2021-38647)

Windows remote PowerShell session activity via wsmprovhost.exe process relationships

Windows Remote PowerShell via PS Classic (wsmprovhost.exe, HostName=ServerRemoteHost)

Windows process creation: child process spawned by winrshost.exe

Pivot detection · T1021.006 · 9 related

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

windows-process-creation-child-process-spawned-by-winrshost-exe-79df3f68

title: "Windows process creation: child process spawned by winrshost.exe"
id: 8ab1f668-de64-47ac-a512-782e7f688383
status: experimental
description: This rule identifies when a process is created as a child of winrshost.exe on Windows, indicating remote command execution via Windows Remote Shell (WinRS). Such activity can be used to run commands on additional hosts and may support lateral movement. It relies on Windows process creation telemetry, matching the parent executable name and excluding cases involving conhost.exe as the spawned image.
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
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_winrshost_command_execution.yml
author: Liran Ravich, Huntrule Team
date: 2025-10-22
tags:
  - attack.lateral-movement
  - attack.t1021.006
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    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
license: DRL-1.1
related:
  - id: 79df3f68-dccb-48e9-9171-b75cbc37c51d
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL