Execution via local SxS Shared Module

 1[metadata]
 2creation_date = "2020/10/28"
 3integration = ["endpoint", "windows"]
 4maturity = "production"
 5updated_date = "2024/05/21"
 6
 7[rule]
 8author = ["Elastic"]
 9description = """
10Identifies the creation, change, or deletion of a DLL module within a Windows SxS local folder. Adversaries may abuse
11shared modules to execute malicious payloads by instructing the Windows module loader to load DLLs from arbitrary local
12paths.
13"""
14from = "now-9m"
15index = ["winlogbeat-*", "logs-endpoint.events.file-*", "logs-windows.sysmon_operational-*", "endgame-*"]
16language = "eql"
17license = "Elastic License v2"
18name = "Execution via local SxS Shared Module"
19note = """## Triage and analysis
20
21The SxS DotLocal folder is a legitimate feature that can be abused to hijack standard modules loading order by forcing an executable on the same application.exe.local folder to load a malicious DLL module from the same directory.
22"""
23references = ["https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-redirection"]
24risk_score = 47
25rule_id = "a3ea12f3-0d4e-4667-8b44-4230c63f3c75"
26setup = """## Setup
27
28If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
29events will not define `event.ingested` and default fallback for EQL rules was not added until version 8.2.
30Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
31`event.ingested` to @timestamp.
32For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
33"""
34severity = "medium"
35tags = [
36    "Domain: Endpoint",
37    "OS: Windows",
38    "Use Case: Threat Detection",
39    "Tactic: Execution",
40    "Data Source: Elastic Endgame",
41    "Data Source: Elastic Defend",
42    "Data Source: Sysmon",
43]
44timestamp_override = "event.ingested"
45type = "eql"
46
47query = '''
48file where host.os.type == "windows" and file.extension : "dll" and file.path : "C:\\*\\*.exe.local\\*.dll"
49'''
50
51
52[[rule.threat]]
53framework = "MITRE ATT&CK"
54[[rule.threat.technique]]
55id = "T1129"
56name = "Shared Modules"
57reference = "https://attack.mitre.org/techniques/T1129/"
58
59
60[rule.threat.tactic]
61id = "TA0002"
62name = "Execution"
63reference = "https://attack.mitre.org/tactics/TA0002/"