sigmamediumHunting

Change PowerShell Policies to an Insecure Level - PowerShell

Detects changing the PowerShell script execution policy to a potentially insecure level using the "Set-ExecutionPolicy" cmdlet.

MITRE ATT&CK

T1059.001

execution

Detection Query

selection_cmdlet:
  ScriptBlockText|contains: Set-ExecutionPolicy
selection_option:
  ScriptBlockText|contains:
    - Unrestricted
    - bypass
filter_optional_chocolatey:
  ScriptBlockText|contains:
    - (New-Object
      System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1')
    - (New-Object
      System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1')
condition: all of selection_* and not 1 of filter_optional_*

Author

frack113

Created

2021-10-20

Data Sources

windowsps_script

Platforms

windows

References

Tags

attack.executionattack.t1059.001

Raw Content

title: Change PowerShell Policies to an Insecure Level - PowerShell
id: 61d0475c-173f-4844-86f7-f3eebae1c66b
related:
    - id: cf2e938e-9a3e-4fe8-a347-411642b28a9f # ProcCreation Registry
      type: similar
    - id: 87e3c4e8-a6a8-4ad9-bb4f-46e7ff99a180 # ProcCreation Cmdlet
      type: similar
    - id: fad91067-08c5-4d1a-8d8c-d96a21b37814 # Registry
      type: similar
status: test
description: Detects changing the PowerShell script execution policy to a potentially insecure level using the "Set-ExecutionPolicy" cmdlet.
references:
    - https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.security/set-executionpolicy?view=powershell-7.4
    - https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_execution_policies?view=powershell-7.4
    - https://adsecurity.org/?p=2604
author: frack113
date: 2021-10-20
modified: 2023-12-14
tags:
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection_cmdlet:
        ScriptBlockText|contains: 'Set-ExecutionPolicy'
    selection_option:
        ScriptBlockText|contains:
            - 'Unrestricted'
            - 'bypass'
    filter_optional_chocolatey:
        ScriptBlockText|contains:
            - "(New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1')"
            - "(New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1')"
    condition: all of selection_* and not 1 of filter_optional_*
falsepositives:
    - Administrator script
level: medium