[metadata]
creation_date = "2020/04/21"
maturity = "production"
updated_date = "2020/11/03"

[rule]
author = ["Elastic"]
description = """
Identifies file permission modifications in common writable directories by a non-root user. Adversaries often drop files
or payloads into a writable directory and change permissions prior to execution.
"""
false_positives = [
    """
    Certain programs or applications may modify files or change ownership in writable directories. These can be exempted
    by username.
    """,
]
from = "now-9m"
index = ["auditbeat-*", "logs-endpoint.events.*"]
language = "kuery"
license = "Elastic License"
name = "File Permission Modification in Writable Directory"
risk_score = 21
rule_id = "9f9a2a82-93a8-4b1a-8778-1780895626d4"
severity = "low"
tags = ["Elastic", "Host", "Linux", "Threat Detection", "Defense Evasion"]
type = "query"

query = '''
event.category:process and event.type:(start or process_started) and
  process.name:(chmod or chown or chattr or chgrp) and
  process.working_directory:(/tmp or /var/tmp or /dev/shm) and
  not user.name:root
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1222"
name = "File and Directory Permissions Modification"
reference = "https://attack.mitre.org/techniques/T1222/"


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

