PSScriptPolicyTest Creation By Unusual Process (via file_event)

title: PSScriptPolicyTest Creation By Unusual Process (via file_event)
id: e515bef6-a0d0-5266-9861-93d6cdd1b389
status: stable
description: This rule detects the creation of the "PSScriptPolicyTest" PowerShell script by an uncommon process. This file is usually generated by Microsoft Powershell to test against Applocker.
references:
    - https://www.paloaltonetworks.com/blog/security-operations/stopping-powershell-without-powershell/
author: Huntrule Team
date: 2026-01-14
tags:
    - attack.stealth
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|contains: '__PSScriptPolicyTest_'
    filter_main_powershell:
        Image:
            - 'C:\Program Files\PowerShell\7-preview\pwsh.exe'
            - 'C:\Program Files\PowerShell\7\pwsh.exe'
            - 'C:\Windows\System32\WindowsPowerShell\v1.0\powershell_ise.exe'
            - 'C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe'
            - 'C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell_ise.exe'
            - 'C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe'
    filter_main_pwsh_preview:
        Image|contains:
            - 'C:\Program Files\WindowsApps\Microsoft.PowerShellPreview'
            - '\AppData\Local\Microsoft\WindowsApps\Microsoft.PowerShellPreview'
        Image|endswith: '\pwsh.exe'
    filter_main_generic:
        Image:
            - 'C:\Windows\System32\dsac.exe'
            - 'C:\Windows\System32\sdiagnhost.exe'
            - 'C:\Windows\System32\ServerManager.exe'
            - 'C:\Windows\System32\wsmprovhost.exe'
            - 'C:\Windows\SysWOW64\sdiagnhost.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium