Powershell Executed From Headless ConHost Process — Sigma Rule

Rule metadata and linked tags

Author: Matt Anderson (Huntress). Source status: test; severity: medium. Source dates: 2024-07-23 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 55e32cee45f25b9d315202f915f37a59845c097a3807a7f45bfb15fb118df928

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: Powershell Executed From Headless ConHost Process
id: 056c7317-9a09-4bd4-9067-d051312752ea
related:
    - id: 00ca75ab-d5ce-43be-b86c-55ff39c6abfc
      type: derived
status: test
description: |
    Detects the use of powershell commands from headless ConHost window.
    The "--headless" flag hides the windows from the user upon execution.
references:
    - https://www.huntress.com/blog/fake-browser-updates-lead-to-boinc-volunteer-computing-software
author: Matt Anderson (Huntress)
date: 2024-07-23
tags:
    - attack.execution
    - attack.stealth
    - attack.t1059.001
    - attack.t1059.003
    - attack.t1564.003
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\conhost.exe'
        - OriginalFileName: 'CONHOST.EXE'
    selection_cli:
        CommandLine|contains|all:
            - '--headless'
            - 'powershell'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_conhost_headless_powershell/info.yml

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.huntress.com/blog/fake-browser-updates-lead-to-boinc-volunteer-computing-software