ROT Encoded Python Script Execution

Last updated 2 months ago on 2024-09-17

Created 2 months ago on 2024-09-17

About

Identifies the execution of a Python script that uses the ROT cipher for letters substitution. Adversaries may use this method to encode and obfuscate part of their malicious code in legit python packages.

Tags

Domain: EndpointOS: WindowsOS: macOSUse Case: Threat DetectionTactic: Defense EvasionData Source: Elastic Defend

Severity

medium

Risk Score

MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

↳ Deobfuscate/Decode Files or Information (T1140)(opens in a new tab or window)

↳ Obfuscated Files or Information (T1027)(opens in a new tab or window)

License

Elastic License v2(opens in a new tab or window)

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-endpoint.events.process-*logs-endpoint.events.file-*
Related Integrations: endpoint(opens in a new tab or window)
Query

sequence by process.entity_id with maxspan=1m
 [process where host.os.type in ("windows", "macos") and event.type == "start" and process.name : "python*"]
 [file where host.os.type in ("windows", "macos") and
  event.action != "deletion" and process.name : "python*" and file.name : "rot_??.cpython-*.pyc*"]

Install detection rules in Elastic Security

Detect ROT Encoded Python Script Execution in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).