Potential WinAPI Calls Via PowerShell Scripts — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems), Nikita Nazarov, oscd.community. Source status: test; severity: high. Source dates: 2020-10-06 / 2023-06-20.

{
  "product": "windows",
  "category": "ps_script",
  "definition": "Requirements: Script Block Logging must be enabled"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: c0081bb2293f19f6e0ae23df988780296bc1edf1a2203390b43eb85ecf262dd7

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential WinAPI Calls Via PowerShell Scripts
id: 03d83090-8cba-44a0-b02f-0b756a050306
related:
    - id: ba3f5c1b-6272-4119-9dbd-0bc8d21c2702
      type: similar
status: test
description: Detects use of WinAPI functions in PowerShell scripts
references:
    - https://speakerdeck.com/heirhabarov/hunting-for-powershell-abuse
author: Nasreddine Bencherchali (Nextron Systems), Nikita Nazarov, oscd.community
date: 2020-10-06
modified: 2023-06-20
tags:
    - attack.execution
    - attack.t1059.001
    - attack.t1106
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    # Note: Add more suspicious combinations in the form of different selections
    selection_injection:
        ScriptBlockText|contains|all:
            - 'VirtualAlloc'
            - 'OpenProcess'
            - 'WriteProcessMemory'
            - 'CreateRemoteThread'
    selection_token_steal:
        ScriptBlockText|contains|all:
            - 'OpenProcessToken'
            - 'LookupPrivilegeValue'
            - 'AdjustTokenPrivileges'
    selection_duplicate_token:
        ScriptBlockText|contains|all:
            - 'OpenProcessToken'
            - 'DuplicateTokenEx'
            - 'CloseHandle'
    selection_process_write_read:
        ScriptBlockText|contains|all:
            - 'WriteProcessMemory'
            - 'VirtualAlloc'
            - 'ReadProcessMemory'
            - 'VirtualFree'
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://speakerdeck.com/heirhabarov/hunting-for-powershell-abuse