Detection rules › Sigma
PSScriptPolicyTest Creation By Uncommon Process
Detects the creation of the "PSScriptPolicyTest" PowerShell script by an uncommon process. This file is usually generated by Microsoft Powershell to test against Applocker.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | No specific technique |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 11: FileCreate |
Rule body
title: PSScriptPolicyTest Creation By Uncommon Process
id: 1027d292-dd87-4a1a-8701-2abe04d7783c
status: test
description: 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: Nasreddine Bencherchali (Nextron Systems)
date: 2023-06-01
modified: 2026-07-28
tags:
- attack.stealth
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'
filter_optional_gethelp:
Image|startswith: 'C:\Program Files\WindowsApps\Microsoft.GetHelp_'
Image|endswith: '\GetHelp.exe'
condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
- Unknown
level: medium
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_* and not 1 of filter_optional_*Stage 1: selection
selection:
TargetFilename|contains: '__PSScriptPolicyTest_'
Stage 2: not filter_main_*
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'
Stage 3: not filter_optional_gethelp
filter_optional_gethelp:
Image|startswith: 'C:\Program Files\WindowsApps\Microsoft.GetHelp_'
Image|endswith: '\GetHelp.exe'
Exclusions
The rule actively suppresses these predicates.
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
TargetFilename | match |
| field:"TargetFilename" kind:match value:"__PSScriptPolicyTest_" |