Invoke-Obfuscation COMPRESS OBFUSCATION - System

Title: Invoke-Obfuscation COMPRESS OBFUSCATION - System
Status: test
Description:Detects Obfuscated Powershell via COMPRESS OBFUSCATION
References:
  -https://github.com/SigmaHQ/sigma/issues/1009
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
• service: system

Detection:
  selection:
    Provider_Name: 'Service Control Manager'
    EventID: '7045'
    ImagePath|contains|all:
      -'new-object'
      -'text.encoding]::ascii'
      -'readtoend'

    ImagePath|contains:
      -':system.io.compression.deflatestream'
      -'system.io.streamreader'

  condition:selection
Falsepositives:
  -Unknown
Level: medium