[metadata]
creation_date = "2020/02/18"
maturity = "production"
updated_date = "2020/11/03"

[rule]
author = ["Elastic"]
description = """
Identifies the use of certutil.exe to encode or decode data. CertUtil is a native Windows component which is part of
Certificate Services. CertUtil is often abused by attackers to encode or decode base64 data for stealthier command and
control or exfiltration.
"""
from = "now-9m"
index = ["winlogbeat-*", "logs-endpoint.events.*"]
language = "kuery"
license = "Elastic License"
name = "Encoding or Decoding Files via CertUtil"
risk_score = 47
rule_id = "fd70c98a-c410-42dc-a2e3-761c71848acf"
severity = "medium"
tags = ["Elastic", "Host", "Windows", "Threat Detection", "Defense Evasion"]
type = "query"

query = '''
event.category:process and event.type:(start or process_started) and
  process.name:certutil.exe and process.args:(-decode or -encode or /decode or /encode)
'''


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

