[metadata]
creation_date = "2024/09/17"
integration = ["endpoint"]
maturity = "production"
updated_date = "2024/09/17"

[rule]
author = ["Elastic"]
description = """
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.
"""
from = "now-9m"
index = ["logs-endpoint.events.process-*", "logs-endpoint.events.file-*"]
language = "eql"
license = "Elastic License v2"
name = "ROT Encoded Python Script Execution"
references = [
    "https://www.elastic.co/security-labs/dprk-code-of-conduct",
    "https://www.reversinglabs.com/blog/fake-recruiter-coding-tests-target-devs-with-malicious-python-packages"
]
risk_score = 47
rule_id = "5ab49127-b1b3-46e6-8a38-9e8512a2a363"
severity = "medium"
tags = [
    "Domain: Endpoint",
    "OS: Windows",
    "OS: macOS",
    "Use Case: Threat Detection",
    "Tactic: Defense Evasion",
    "Data Source: Elastic Defend",
]
type = "eql"

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*"]
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1140"
name = "Deobfuscate/Decode Files or Information"
reference = "https://attack.mitre.org/techniques/T1140/"
[[rule.threat.technique]]
id = "T1027"
name = "Obfuscated Files or Information"
reference = "https://attack.mitre.org/techniques/T1027/"
[[rule.threat.technique.subtechnique]]
id = "T1027.013"
name = "Encrypted/Encoded File"
reference = "https://attack.mitre.org/techniques/T1027/013/"


[rule.threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"