ImageLoad via Windows Update Auto Update Client

 1[metadata]
 2creation_date = "2020/10/13"
 3integration = ["endpoint", "windows"]
 4maturity = "production"
 5min_stack_comments = "New fields added: required_fields, related_integrations, setup"
 6min_stack_version = "8.3.0"
 7updated_date = "2023/06/22"
 8
 9[rule]
10author = ["Elastic"]
11description = """
12Identifies abuse of the Windows Update Auto Update Client (wuauclt.exe) to load an arbitrary DLL. This behavior is used
13as a defense evasion technique to blend-in malicious activity with legitimate Windows software.
14"""
15from = "now-9m"
16index = ["logs-endpoint.events.*", "winlogbeat-*", "logs-windows.*", "endgame-*"]
17language = "eql"
18license = "Elastic License v2"
19name = "ImageLoad via Windows Update Auto Update Client"
20note = """## Setup
21
22If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
23"""
24references = ["https://dtm.uk/wuauclt/"]
25risk_score = 47
26rule_id = "edf8ee23-5ea7-4123-ba19-56b41e424ae3"
27severity = "medium"
28tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Defense Evasion", "Data Source: Elastic Endgame", "Data Source: Elastic Defend"]
29timeline_id = "e70679c2-6cde-4510-9764-4823df18f7db"
30timeline_title = "Comprehensive Process Timeline"
31timestamp_override = "event.ingested"
32type = "eql"
33
34query = '''
35process where host.os.type == "windows" and event.type == "start" and
36  (process.pe.original_file_name == "wuauclt.exe" or process.name : "wuauclt.exe") and
37   /* necessary windows update client args to load a dll */
38   process.args : "/RunHandlerComServer" and process.args : "/UpdateDeploymentProvider" and
39   /* common paths writeable by a standard user where the target DLL can be placed */
40   process.args : ("C:\\Users\\*.dll", "C:\\ProgramData\\*.dll", "C:\\Windows\\Temp\\*.dll", "C:\\Windows\\Tasks\\*.dll")
41'''
42
43
44[[rule.threat]]
45framework = "MITRE ATT&CK"
46[[rule.threat.technique]]
47id = "T1218"
48name = "System Binary Proxy Execution"
49reference = "https://attack.mitre.org/techniques/T1218/"
50
51
52[rule.threat.tactic]
53id = "TA0005"
54name = "Defense Evasion"
55reference = "https://attack.mitre.org/tactics/TA0005/"