Remote PowerShell Session Host Process (WinRM)

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Roberto Rodriguez @Cyb3rWard0g
Source: github.com/SigmaHQ/sigma

Detects remote PowerShell sections by monitoring for wsmprovhost (WinRM host process) as a parent or child process (sign of an active PowerShell remote session).

Known false positives

Legitimate usage of remote Powershell, e.g. for monitoring purposes.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059.001` Command and Scripting Interpreter: PowerShell
Lateral Movement	`T1021.006` Remote Services: Windows Remote Management

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Remote PowerShell Session Host Process (WinRM)
id: 734f8d9b-42b8-41b2-bcf5-abaf49d5a3c8
status: test
description: Detects remote PowerShell sections by monitoring for wsmprovhost (WinRM host process) as a parent or child process (sign of an active PowerShell remote session).
references:
    - https://threathunterplaybook.com/hunts/windows/190511-RemotePwshExecution/notebook.html
author: Roberto Rodriguez @Cyb3rWard0g
date: 2019-09-12
modified: 2022-10-09
tags:
    - attack.execution
    - attack.lateral-movement
    - attack.t1059.001
    - attack.t1021.006
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - Image|endswith: '\wsmprovhost.exe'
        - ParentImage|endswith: '\wsmprovhost.exe'
    condition: selection
falsepositives:
    - Legitimate usage of remote Powershell, e.g. for monitoring purposes.
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    - Image|endswith: '\wsmprovhost.exe'
    - ParentImage|endswith: '\wsmprovhost.exe'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\wsmprovhost.exe` corpus 3 (sigma 3)	`field:"Image" kind:ends_with value:"\wsmprovhost.exe"`
`ParentImage`	ends_with	`\wsmprovhost.exe` corpus 2 (sigma 2)	`field:"ParentImage" kind:ends_with value:"\wsmprovhost.exe"`