1type: trigger
2name: sigmahq/proc_creation_win_hktl_invoke_obfuscation_obfuscated_iex_commandline
3description: |
4  Detects all variations of obfuscated powershell IEX invocation code generated by Invoke-Obfuscation framework from the following code block
5filter: |
6  (evt.Meta.service == 'sysmon' && evt.Parsed.EventID == '1') && (evt.Parsed.CommandLine matches '\\$PSHome\\[\\s*\\d{1,3}\\s*\\]\\s*\\+\\s*\\$PSHome\\[' || evt.Parsed.CommandLine matches '\\$ShellId\\[\\s*\\d{1,3}\\s*\\]\\s*\\+\\s*\\$ShellId\\[' || evt.Parsed.CommandLine matches '\\$env:Public\\[\\s*\\d{1,3}\\s*\\]\\s*\\+\\s*\\$env:Public\\[' || evt.Parsed.CommandLine matches '\\$env:ComSpec\\[(\\s*\\d{1,3}\\s*,){2}' || evt.Parsed.CommandLine matches '\\*mdr\\*\\W\\s*\\)\\.Name' || evt.Parsed.CommandLine matches '\\$VerbosePreference\\.ToString\\(' || evt.Parsed.CommandLine matches '\\[String\\]\\s*\\$VerbosePreference')
7blackhole: 2m
8#status: test
9labels:
10  service: windows
11  confidence: 1
12  spoofable: 0
13  classification:
14   - attack.t1027
15   - attack.t1059.001
16
17  label: "Invoke-Obfuscation Obfuscated IEX Invocation"
18  behavior : "windows:audit"
19  remediation: false
20
21scope:
22  type: ParentProcessId
23  expression: evt.Parsed.ParentProcessId
24
25