Invoke-Obfuscation Obfuscated IEX Invocation - System

 1title: Invoke-Obfuscation Obfuscated IEX Invocation - System
 2id: 51aa9387-1c53-4153-91cc-d73c59ae1ca9
 3status: test
 4description: Detects all variations of obfuscated powershell IEX invocation code generated by Invoke-Obfuscation framework from the code block linked in the references
 5references:
 6    - https://github.com/danielbohannon/Invoke-Obfuscation/blob/f20e7f843edd0a3a7716736e9eddfa423395dd26/Out-ObfuscatedStringCommand.ps1#L873-L888
 7author: Daniel Bohannon (@Mandiant/@FireEye), oscd.community
 8date: 2019-11-08
 9modified: 2022-11-27
10tags:
11    - attack.defense-evasion
12    - attack.t1027
13logsource:
14    product: windows
15    service: system
16detection:
17    selection_eid:
18        EventID: 7045
19    selection_imagepath:
20        - ImagePath|re: '\$PSHome\[\s*\d{1,3}\s*\]\s*\+\s*\$PSHome\['
21        - ImagePath|re: '\$ShellId\[\s*\d{1,3}\s*\]\s*\+\s*\$ShellId\['
22        - ImagePath|re: '\$env:Public\[\s*\d{1,3}\s*\]\s*\+\s*\$env:Public\['
23        - ImagePath|re: '\$env:ComSpec\[(\s*\d{1,3}\s*,){2}'
24        - ImagePath|re: '\\*mdr\*\W\s*\)\.Name'
25        - ImagePath|re: '\$VerbosePreference\.ToString\('
26        - ImagePath|re: '\String\]\s*\$VerbosePreference'
27    condition: all of selection_*
28falsepositives:
29    - Unknown
30level: high