Files
sigma-rules/rta/linux_persistence_direct_crontab_modification.py
T
2024-09-11 17:44:37 +05:30

54 lines
1.5 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.
import sys
from pathlib import Path
from . import RtaMetadata, common
metadata = RtaMetadata(
uuid="a1286125-bf4b-40bb-819a-b7c5de83fafb",
platforms=["linux"],
endpoint=[
{
"rule_name": "Potential Persistence via Direct Crontab Modification",
"rule_id": "b3bcbab6-e216-4d70-bdee-2b69affbb386",
},
],
techniques=["T1053"],
)
@common.requires_os(*metadata.platforms)
def main() -> None:
# Path for the fake script
rta_script = "/dev/shm/rta"
# Create fake executable
masquerade = "/tmp/crontab"
source = common.get_path("bin", "linux.ditto_and_spawn")
common.copy_file(source, masquerade)
common.execute(["chmod", "+x", masquerade])
# Create a fake script that executes the fake binary
with Path(rta_script).open("w", encoding="utf-8") as script:
script.write("#!/bin/bash\n")
script.write("/tmp/crontab -\n")
# Make the script executable
common.execute(["chmod", "+x", rta_script])
# Execute the fake script
common.log("Launching fake script")
common.execute([rta_script], timeout=5, kill=True, shell=True) # noqa: S604
# Cleanup
common.remove_file(rta_script)
common.remove_file(masquerade)
if __name__ == "__main__":
sys.exit(main())