
title: Invoke-Obfuscation COMPRESS OBFUSCATION
author: Timur Zinniatullin, oscd.community
date: 2020/10/18
description: Detects Obfuscated Powershell via COMPRESS OBFUSCATION
detection:
  SELECTION_1:
    EventID: 1
  SELECTION_2:
    CommandLine|re: (?i).*new-object.*(?:system\.io\.compression\.deflatestream|system\.io\.streamreader).*text\.encoding\]::ascii.*readtoend
  condition: (SELECTION_1 and SELECTION_2)
falsepositives:
- unknown
id: 7eedcc9d-9fdb-4d94-9c54-474e8affc0c7
level: medium
logsource:
  category: process_creation
  product: windows
references:
- https://github.com/Neo23x0/sigma/issues/1009
status: experimental
tags:
- attack.defense_evasion
- attack.t1027
- attack.execution
- attack.t1059.001
ruletype: SIGMA
