Invoke-Obfuscation COMPRESS OBFUSCATION

Description

Detects Obfuscated Powershell via COMPRESS OBFUSCATION

Query · sigma

selection:
  CommandLine|contains|all:
  - new-object
  - text.encoding]::ascii
  CommandLine|contains:
  - system.io.compression.deflatestream
  - system.io.streamreader
  - readtoend(
condition: selection

Known false positives

  • Unknown
Raw source Invoke-Obfuscation COMPRESS OBFUSCATION · Sigma
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Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified. 
title: Invoke-Obfuscation COMPRESS OBFUSCATION
id: 7eedcc9d-9fdb-4d94-9c54-474e8affc0c7
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: 2022-12-29
tags:
    - attack.stealth
    - attack.t1027
    - attack.execution
    - attack.t1059.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
            - 'new-object'
            - 'text.encoding]::ascii'
        CommandLine|contains:
            - 'system.io.compression.deflatestream'
            - 'system.io.streamreader'
            - 'readtoend('
    condition: selection
falsepositives:
    - Unknown
level: medium

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