Detection rules › Sigma
Invoke-Obfuscation STDIN+ Launcher - System
Detects Obfuscated use of stdin to execute PowerShell
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059.001 Command and Scripting Interpreter: PowerShell |
| Stealth | T1027 Obfuscated Files or Information |
Event coverage
| Provider | Event |
|---|---|
| Service-Control-Manager | Event ID 7045 |
Rule body yaml
title: Invoke-Obfuscation STDIN+ Launcher - System
id: 72862bf2-0eb1-11eb-adc1-0242ac120002
status: test
description: Detects Obfuscated use of stdin to execute PowerShell
references:
- https://github.com/SigmaHQ/sigma/issues/1009 # (Task 25)
author: Jonathan Cheong, oscd.community
date: 2020-10-15
modified: 2022-11-29
tags:
- attack.stealth
- attack.t1027
- attack.execution
- attack.t1059.001
logsource:
product: windows
service: system
detection:
selection_main:
Provider_Name: 'Service Control Manager'
EventID: 7045
# ImagePath|re: 'cmd.{0,5}(?:\/c|\/r).+powershell.+(?:\$\{?input\}?|noexit).+\"'
# Example 1: c:\windows\sYstEm32\CmD.eXE /C"echO\Invoke-Expression (New-Object Net.WebClient).DownloadString | POwersHELl -NoEXiT -"
# Example 2: c:\WiNDOws\sysTEm32\cmd.EXe /C " ECHo Invoke-Expression (New-Object Net.WebClient).DownloadString | POwersHELl -nol ${EXEcUtIONCONTeXT}.INvOkEComMANd.InvOKEScRIPt( $InpUt )"
ImagePath|contains|all:
- 'cmd'
- 'powershell'
ImagePath|contains:
- '/c'
- '/r'
selection_other:
- ImagePath|contains: 'noexit'
- ImagePath|contains|all:
- 'input'
- '$'
condition: all of selection_*
falsepositives:
- Unknown
level: high
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_main
selection_main:
Provider_Name: 'Service Control Manager'
EventID: 7045
ImagePath|contains|all:
- 'cmd'
- 'powershell'
ImagePath|contains:
- '/c'
- '/r'
Stage 2: selection_other
selection_other:
- ImagePath|contains: 'noexit'
- ImagePath|contains|all:
- 'input'
- '$'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
ImagePath | match |
|
Provider_Name | eq |
|