Potential DLL Side-Loading via Trusted Microsoft Programs

 1[metadata]
 2creation_date = "2020/09/03"
 3integration = ["endpoint", "windows", "m365_defender"]
 4maturity = "production"
 5updated_date = "2024/10/15"
 6min_stack_version = "8.14.0"
 7min_stack_comments = "Breaking change at 8.14.0 for the Windows Integration."
 8
 9[rule]
10author = ["Elastic"]
11description = """
12Identifies an instance of a Windows trusted program that is known to be vulnerable to DLL Search Order Hijacking
13starting after being renamed or from a non-standard path. This is uncommon behavior and may indicate an attempt to evade
14defenses via side loading a malicious DLL within the memory space of one of those processes.
15"""
16from = "now-9m"
17index = ["winlogbeat-*", "logs-endpoint.events.process-*", "logs-windows.sysmon_operational-*", "endgame-*", "logs-m365_defender.event-*"]
18language = "eql"
19license = "Elastic License v2"
20name = "Potential DLL Side-Loading via Trusted Microsoft Programs"
21risk_score = 73
22rule_id = "1160dcdb-0a0a-4a79-91d8-9b84616edebd"
23setup = """## Setup
24
25If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
26events will not define `event.ingested` and default fallback for EQL rules was not added until version 8.2.
27Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
28`event.ingested` to @timestamp.
29For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
30"""
31severity = "high"
32tags = [
33    "Domain: Endpoint",
34    "OS: Windows",
35    "Use Case: Threat Detection",
36    "Tactic: Defense Evasion",
37    "Tactic: Execution",
38    "Data Source: Elastic Endgame",
39    "Data Source: Elastic Defend",
40    "Data Source: Sysmon",
41    "Data Source: Microsoft Defender for Endpoint",
42]
43timestamp_override = "event.ingested"
44type = "eql"
45
46query = '''
47process where host.os.type == "windows" and event.type == "start" and
48  process.pe.original_file_name in ("WinWord.exe", "EXPLORER.EXE", "w3wp.exe", "DISM.EXE") and
49  not (process.name : ("winword.exe", "explorer.exe", "w3wp.exe", "Dism.exe") or
50         process.executable : ("?:\\Windows\\explorer.exe",
51                               "?:\\Program Files\\Microsoft Office\\root\\Office*\\WINWORD.EXE",
52                               "?:\\Program Files?(x86)\\Microsoft Office\\root\\Office*\\WINWORD.EXE",
53                               "?:\\Windows\\System32\\Dism.exe",
54                               "?:\\Windows\\SysWOW64\\Dism.exe",
55                               "?:\\Windows\\System32\\inetsrv\\w3wp.exe")
56         )
57'''
58
59
60[[rule.threat]]
61framework = "MITRE ATT&CK"
62[[rule.threat.technique]]
63id = "T1036"
64name = "Masquerading"
65reference = "https://attack.mitre.org/techniques/T1036/"
66
67[[rule.threat.technique]]
68id = "T1574"
69name = "Hijack Execution Flow"
70reference = "https://attack.mitre.org/techniques/T1574/"
71[[rule.threat.technique.subtechnique]]
72id = "T1574.002"
73name = "DLL Side-Loading"
74reference = "https://attack.mitre.org/techniques/T1574/002/"
75
76
77
78[rule.threat.tactic]
79id = "TA0005"
80name = "Defense Evasion"
81reference = "https://attack.mitre.org/tactics/TA0005/"