sigmamediumHunting

Invoke-Obfuscation COMPRESS OBFUSCATION

Detects Obfuscated Powershell via COMPRESS OBFUSCATION

MITRE ATT&CK

defense-evasionexecution

Detection Query

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

Author

Timur Zinniatullin, oscd.community

Created

2020-10-18

Data Sources

windowsProcess Creation Events

Platforms

windows

References

https://github.com/SigmaHQ/sigma/issues/1009

Tags

attack.defense-evasionattack.t1027attack.executionattack.t1059.001

Raw Content

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.defense-evasion
    - 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