Sigma rule: Invoke-Obfuscation COMPRESS OBFUSCATION - PowerShell Module

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-619586a3be61, updated 2022-11-29T00:00:00.000Z.

Rule

Title
Invoke-Obfuscation COMPRESS OBFUSCATION - PowerShell Module
Status
test
Level
medium
Author
Timur Zinniatullin, oscd.community
Date
2020-10-18
Modified
2022-11-29
File
rules/windows/powershell/powershell_module/posh_pm_invoke_obfuscation_via_compress.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects Obfuscated Powershell via COMPRESS OBFUSCATION

Log source

product
windows
category
ps_module
definition
0ad03ef1-f21b-4a79-8ce8-e6900c54b65b

Detection

selection_4103:
    Payload|contains|all:
        - 'new-object'
        - 'text.encoding]::ascii'
    Payload|contains:
        - 'system.io.compression.deflatestream'
        - 'system.io.streamreader'
    Payload|endswith: 'readtoend'
condition: selection_4103

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.stealth
  • attack.t1027
  • attack.execution
  • attack.t1059.001

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/powershell/powershell_module/posh_pm_invoke_obfuscation_via_compress.yml

Sources and licences

  • SigmaHQ

    "Invoke-Obfuscation COMPRESS OBFUSCATION - PowerShell Module" by Timur Zinniatullin, oscd.community (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/powershell/powershell_module/posh_pm_invoke_obfuscation_via_compress.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Invoke-Obfuscation COMPRESS OBFUSCATION - PowerShell Module",
entity page, dataset version ref-619586a3be61, updated 2022-11-29T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/7034cbbb-cc55-4dc2-8dad-36c0b942e8f1 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 7034cbbb-cc55-4dc2-8dad-36c0b942e8f1, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.