title: Invoke-Obfuscation Obfuscated IEX Invocation
id: 4bf943c6-5146-4273-98dd-e958fd1e3abf
status: test
description: Detects all variations of obfuscated powershell IEX invocation code generated by Invoke-Obfuscation framework from the following code block
references:
  - https://github.com/danielbohannon/Invoke-Obfuscation/blob/master/Out-ObfuscatedStringCommand.ps1#L873-L888
author: 'Daniel Bohannon (@Mandiant/@FireEye), oscd.community'
date: 2019/11/08
modified: 2021/11/27
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    - CommandLine|re: '\$PSHome\[\s*\d{1,3}\s*\]\s*\+\s*\$PSHome\['
    - CommandLine|re: '\$ShellId\[\s*\d{1,3}\s*\]\s*\+\s*\$ShellId\['
    - CommandLine|re: '\$env:Public\[\s*\d{1,3}\s*\]\s*\+\s*\$env:Public\['
    - CommandLine|re: '\$env:ComSpec\[(\s*\d{1,3}\s*,){2}'
    - CommandLine|re: '\\\\*mdr\\\\*\W\s*\)\.Name'
    - CommandLine|re: '\$VerbosePreference\.ToString\('
    - CommandLine|re: '\\\\String\]\s*\$VerbosePreference'
  condition: selection
falsepositives:
  - Unknown
level: high
tags:
  - attack.defense_evasion
  - attack.t1027
  - attack.execution
  - attack.t1059.001
