PowerShell Set-Acl On Windows Folder

title: PowerShell Set-Acl On Windows Folder
id: 0944e002-e3f6-4eb5-bf69-3a3067b53d73 # ProcCreation Susp
related:
    - id: cae80281-ef23-44c5-873b-fd48d2666f49 # PsScript Low
      type: derived
    - id: bdeb2cff-af74-4094-8426-724dc937f20a # ProcCreation Low
      type: derived
    - id: 3bf1d859-3a7e-44cb-8809-a99e066d3478 # PsScript High
      type: derived
status: test
description: Detects PowerShell scripts to set the ACL to a file in the Windows folder
references:
    - https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.security/set-acl?view=powershell-5.1
    - https://github.com/redcanaryco/atomic-red-team/blob/74438b0237d141ee9c99747976447dc884cb1a39/atomics/T1505.005/T1505.005.md
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-10-18
tags:
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName:
              - 'PowerShell.EXE'
              - 'pwsh.dll'
        - Image|endswith:
              - '\powershell.exe'
              - '\pwsh.exe'
    selection_cmdlet:
        CommandLine|contains|all:
            - 'Set-Acl '
            - '-AclObject '
    selection_paths:
        # Note: Add more suspicious paths
        CommandLine|contains:
            - '-Path "C:\Windows'
            - "-Path 'C:\\Windows"
            - '-Path %windir%'
            - '-Path $env:windir'
    selection_permissions:
        # Note: Add more suspicious permissions
        CommandLine|contains:
            - 'FullControl'
            - 'Allow'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high