command_and_control_certutil_network_connection.toml

[metadata]
creation_date = "2020/03/19"
maturity = "production"
updated_date = "2021/05/26"

[rule]
author = ["Elastic"]
description = """
Identifies certutil.exe making a network connection. Adversaries could abuse certutil.exe to download a certificate, or
malware, from a remote URL.
"""
from = "now-9m"
index = ["winlogbeat-*", "logs-endpoint.events.*", "logs-windows.*"]
language = "eql"
license = "Elastic License v2"
name = "Network Connection via Certutil"
references = ["https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml"]
risk_score = 21
rule_id = "3838e0e3-1850-4850-a411-2e8c5ba40ba8"
severity = "low"
tags = ["Elastic", "Host", "Windows", "Threat Detection", "Command and Control"]
type = "eql"

query = '''
sequence by process.entity_id
  [process where process.name : "certutil.exe" and event.type == "start"]
  [network where process.name : "certutil.exe" and
    not cidrmatch(destination.ip, "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24",
                                  "192.0.0.0/29", "192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32",
                                  "192.0.0.171/32", "192.0.2.0/24", "192.31.196.0/24", "192.52.193.0/24",
                                  "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4", "100.64.0.0/10", "192.175.48.0/24",
                                  "198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1",
                                  "FE80::/10", "FF00::/8")]
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1105"
name = "Ingress Tool Transfer"
reference = "https://attack.mitre.org/techniques/T1105/"


[rule.threat.tactic]
id = "TA0011"
name = "Command and Control"
reference = "https://attack.mitre.org/tactics/TA0011/"