Mika Ayenson
51 lines
1.4 KiB
Python
51 lines
1.4 KiB
Python
# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
|
|
# or more contributor license agreements. Licensed under the Elastic License
|
|
# 2.0; you may not use this file except in compliance with the Elastic License
|
|
# 2.0.
|
|
|
|
# Name: Certutil Encode / Decode
|
|
# RTA: certutil_file_obfuscation.py
|
|
# ATT&CK: T1140
|
|
# signal.rule.name: Encoding or Decoding Files via CertUtil
|
|
# Description: Uses certutil to create an encoded copy of cmd.exe. Then uses certutil to decode that copy.
|
|
|
|
import os
|
|
|
|
from . import common
|
|
from . import RtaMetadata
|
|
|
|
|
|
metadata = RtaMetadata(
|
|
uuid="7b2c1b3e-2097-4e2f-bf5c-e157a91b8001",
|
|
platforms=["windows"],
|
|
endpoint=[],
|
|
siem=[{"rule_id": "fd70c98a-c410-42dc-a2e3-761c71848acf", "rule_name": "Suspicious CertUtil Commands"}],
|
|
techniques=["T1140"],
|
|
)
|
|
|
|
|
|
@common.requires_os(metadata.platforms)
|
|
def main():
|
|
common.log("Encoding target")
|
|
encoded_file = os.path.abspath("encoded.txt")
|
|
decoded_file = os.path.abspath("decoded.exe")
|
|
common.execute(
|
|
[
|
|
"c:\\Windows\\System32\\certutil.exe",
|
|
"-encode",
|
|
"c:\\windows\\system32\\cmd.exe",
|
|
encoded_file,
|
|
]
|
|
)
|
|
|
|
common.log("Decoding target")
|
|
common.execute(["c:\\Windows\\System32\\certutil.exe", "-decode", encoded_file, decoded_file])
|
|
|
|
common.log("Cleaning up")
|
|
common.remove_file(encoded_file)
|
|
common.remove_file(decoded_file)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
exit(main())
|