Possible PowerShell Downgrade Attack (via process_creation)

title: Possible PowerShell Downgrade Attack (via process_creation)
id: 48a9b620-ffea-536d-b19a-1038fa306781
status: stable
description: This rule detects PowerShell downgrade attack by comparing the host versions with the actually used engine version 2.0
references:
    - https://attack.mitre.org/techniques/T1059/001/
    - http://www.leeholmes.com/blog/2017/03/17/detecting-and-preventing-powershell-downgrade-attacks/
    - https://github.com/r00t-3xp10it/hacking-material-books/blob/43cb1e1932c16ff1f58b755bc9ab6b096046853f/obfuscation/simple_obfuscation.md#bypass-or-avoid-amsi-by-version-downgrade-
author: Huntrule Team
date: 2026-07-05
tags:
    - attack.execution
    - attack.t1059.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\powershell.exe'
        CommandLine|contains:
            - ' -version 2 '
            - ' -versio 2 '
            - ' -versi 2 '
            - ' -vers 2 '
            - ' -ver 2 '
            - ' -ve 2 '
            - ' -v 2 '
    condition: selection
falsepositives:
    - Unknown
level: medium