win_invoke_obfuscation_obfuscated_iex_commandline.yml

title: Invoke-Obfuscation Obfuscated IEX Invocation
id: 4bf943c6-5146-4273-98dd-e958fd1e3abf
description: "Detects all variations of obfuscated powershell IEX invocation code generated by Invoke-Obfuscation framework from the following code block \u2014 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
tags:
    - attack.defense_evasion
    - attack.t1027
logsource:
    product: windows
    service: process_creation
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