[metadata]
creation_date = "2023/09/27"
integration = ["endpoint"]
maturity = "production"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"
updated_date = "2023/09/27"

[rule]
author = ["Elastic"]
description = """
Identifies binaries that are loaded and with an invalid code signature. This may indicate an attempt to masquerade as a
signed binary.
"""
from = "now-119m"
interval = "60m"
index = ["logs-endpoint.events.*"]
language = "eql"
license = "Elastic License v2"
name = "Image Loaded with Invalid Signature"
risk_score = 21
rule_id = "fd9484f2-1c56-44ae-8b28-dc1354e3a0e8"
severity = "low"
tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Defense Evasion", "Rule Type: BBR", "Data Source: Elastic Defend"]
timestamp_override = "event.ingested"
building_block_type = "default"
type = "eql"

query = '''
library where host.os.type == "windows" and event.action == "load" and
  dll.code_signature.status : ("errorUntrustedRoot", "errorBadDigest", "errorUntrustedRoot") and
  (dll.Ext.relative_file_creation_time <= 500 or dll.Ext.relative_file_name_modify_time <= 500) and
  not startswith~(dll.name, process.name) and
  not dll.path : (
    "?:\\Windows\\System32\\DriverStore\\FileRepository\\*"
  )
'''

[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1036"
name = "Masquerading"
reference = "https://attack.mitre.org/techniques/T1036/"

[[rule.threat.technique.subtechnique]]
id = "T1036.001"
name = "Invalid Code Signature"
reference = "https://attack.mitre.org/techniques/T1036/001/"


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