Detection rules › Sigma
Invoke-Obfuscation COMPRESS OBFUSCATION - PowerShell Module
Detects Obfuscated Powershell via COMPRESS OBFUSCATION
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059.001 Command and Scripting Interpreter: PowerShell |
| Stealth | T1027 Obfuscated Files or Information |
Event coverage
| Provider | Event | Title |
|---|---|---|
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
Rule body yaml
title: Invoke-Obfuscation COMPRESS OBFUSCATION - PowerShell Module
id: 7034cbbb-cc55-4dc2-8dad-36c0b942e8f1
related:
- id: 20e5497e-331c-4cd5-8d36-935f6e2a9a07
type: derived
status: test
description: Detects Obfuscated Powershell via COMPRESS OBFUSCATION
references:
- https://github.com/SigmaHQ/sigma/issues/1009 # (Task 19)
author: Timur Zinniatullin, oscd.community
date: 2020-10-18
modified: 2022-11-29
tags:
- attack.stealth
- attack.t1027
- attack.execution
- attack.t1059.001
logsource:
product: windows
category: ps_module
definition: 0ad03ef1-f21b-4a79-8ce8-e6900c54b65b
detection:
selection_4103:
Payload|contains|all:
- 'new-object'
- 'text.encoding]::ascii'
Payload|contains:
- 'system.io.compression.deflatestream'
- 'system.io.streamreader'
Payload|endswith: 'readtoend'
condition: selection_4103
falsepositives:
- Unknown
level: medium
Stages and Predicates
Stage 0: condition
selection_4103Stage 1: selection_4103
selection_4103:
Payload|contains|all:
- 'new-object'
- 'text.encoding]::ascii'
Payload|contains:
- 'system.io.compression.deflatestream'
- 'system.io.streamreader'
Payload|endswith: 'readtoend'
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.