Unsigned DLL Loaded by an Elastic Signed Binary

[rule]
description = """
Identifies the load of an unsigned or untrusted DLL by an Elastic signed binary. This may indicate a potential DLL
sideloading attempt.
"""
id = "b3edbd4f-d829-49fe-a638-8ef2dc56e8fd"
license = "Elastic License v2"
name = "Unsigned DLL Loaded by an Elastic Signed Binary"
os_list = ["windows"]
version = "1.0.19"

query = '''
library where

 process.code_signature.subject_name == "Elasticsearch, Inc." and

 (dll.code_signature.exists == false or
  (dll.code_signature.trusted == false and not dll.code_signature.status : ("trusted", "errorExpired", "errorCode_endpoint*"))) and

  /* loaded from current dir */
  endswith~(substring(dll.path, 0, length(dll.path) - (length(dll.name) + 1)), substring(process.executable, 0, length(process.executable) - (length(process.name) + 1))) and

  not startswith~(dll.name, process.name)
'''

min_endpoint_version = "8.0.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1574"
name = "Hijack Execution Flow"
reference = "https://attack.mitre.org/techniques/T1574/"
[[threat.technique.subtechnique]]
id = "T1574.001"
name = "DLL"
reference = "https://attack.mitre.org/techniques/T1574/001/"



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

[internal]
min_endpoint_version = "8.0.0"