posh_ps_invoke_obfuscation_var.yml

title: Invoke-Obfuscation VAR+ Launcher - PowerShell
id: 0adfbc14-0ed1-11eb-adc1-0242ac120002
status: test
description: Detects Obfuscated use of Environment Variables to execute PowerShell
references:
    - https://github.com/SigmaHQ/sigma/issues/1009  # (Task 24)
author: Jonathan Cheong, oscd.community
date: 2020/10/15
modified: 2024/04/05
tags:
    - attack.defense_evasion
    - attack.t1027
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection_4104:
        ScriptBlockText|re: 'cmd.{0,5}(?:/c|/r)(?:\s|)"set\s[a-zA-Z]{3,6}.*(?:\{\d\}){1,}\\"\s+?-f(?:.*\)){1,}.*"'
    condition: selection_4104
falsepositives:
    - Unknown
level: high