title: Invoke-Obfuscation Obfuscated IEX Invocation
id: 1b9dc62e-6e9e-42a3-8990-94d7a10007f7
description: Detects all variations of obfuscated powershell IEX invocation code generated by Invoke-Obfuscation framework from the following code block \u2014
references:
  - https://github.com/danielbohannon/Invoke-Obfuscation/blob/master/Out-ObfuscatedStringCommand.ps1#L873-L888
status: experimental
author: 'Daniel Bohannon (@Mandiant/@FireEye), oscd.community'
date: 2019/11/08
modified: 2022/01/27
tags:
    - attack.defense_evasion
    - attack.t1027
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: ps_script
    definition: Script block logging must be enabled
detection:
    selection_iex:
        - ScriptBlockText|re: '\$PSHome\[\s*\d{1,3}\s*\]\s*\+\s*\$PSHome\['
        - ScriptBlockText|re: '\$ShellId\[\s*\d{1,3}\s*\]\s*\+\s*\$ShellId\['
        - ScriptBlockText|re: '\$env:Public\[\s*\d{1,3}\s*\]\s*\+\s*\$env:Public\['
        - ScriptBlockText|re: '\$env:ComSpec\[(\s*\d{1,3}\s*,){2}'
        - ScriptBlockText|re: '\\\\*mdr\\\\*\W\s*\)\.Name'
        - ScriptBlockText|re: '\$VerbosePreference\.ToString\('
    condition: selection_iex
falsepositives:
    - Unknown
level: high
