
title: Invoke-Obfuscation COMPRESS OBFUSCATION
author: Timur Zinniatullin, oscd.community
date: 2020/10/18
description: Detects Obfuscated Powershell via COMPRESS OBFUSCATION
detection:
  SELECTION_1:
    ServiceFileName|re: (?i).*new-object.*(?:system\.io\.compression\.deflatestream|system\.io\.streamreader).*text\.encoding\]::ascii.*readtoend
  SELECTION_2:
    EventID: 4697
  condition: (SELECTION_1 and SELECTION_2)
falsepositives:
- unknown
id: 7a922f1b-2635-4d6c-91ef-af228b198ad3
level: medium
logsource:
  product: windows
  service: security
modified: 2021/09/18
references:
- https://github.com/Neo23x0/sigma/issues/1009
related:
- id: 175997c5-803c-4b08-8bb0-70b099f47595
  type: derived
status: experimental
tags:
- attack.defense_evasion
- attack.t1027
- attack.execution
- attack.t1059.001
ruletype: SIGMA
