Process Execution from an Unusual Directory

 1[metadata]
 2creation_date = "2020/10/30"
 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 process execution from suspicious default Windows directories. This is sometimes done by adversaries to hide
13malware in trusted paths.
14"""
15from = "now-9m"
16index = ["winlogbeat-*", "logs-endpoint.events.*", "logs-windows.*", "endgame-*"]
17language = "eql"
18license = "Elastic License v2"
19name = "Process Execution from an Unusual Directory"
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"""
24risk_score = 47
25rule_id = "ebfe1448-7fac-4d59-acea-181bd89b1f7f"
26severity = "medium"
27tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Defense Evasion", "Data Source: Elastic Endgame", "Data Source: Elastic Defend"]
28timestamp_override = "event.ingested"
29type = "eql"
30
31query = '''
32process where host.os.type == "windows" and event.type == "start" and
33 /* add suspicious execution paths here */
34process.executable : ("C:\\PerfLogs\\*.exe","C:\\Users\\Public\\*.exe","C:\\Windows\\Tasks\\*.exe","C:\\Intel\\*.exe","C:\\AMD\\Temp\\*.exe","C:\\Windows\\AppReadiness\\*.exe",
35"C:\\Windows\\ServiceState\\*.exe","C:\\Windows\\security\\*.exe","C:\\Windows\\IdentityCRL\\*.exe","C:\\Windows\\Branding\\*.exe","C:\\Windows\\csc\\*.exe",
36 "C:\\Windows\\DigitalLocker\\*.exe","C:\\Windows\\en-US\\*.exe","C:\\Windows\\wlansvc\\*.exe","C:\\Windows\\Prefetch\\*.exe","C:\\Windows\\Fonts\\*.exe",
37 "C:\\Windows\\diagnostics\\*.exe","C:\\Windows\\TAPI\\*.exe","C:\\Windows\\INF\\*.exe","C:\\Windows\\System32\\Speech\\*.exe","C:\\windows\\tracing\\*.exe",
38 "c:\\windows\\IME\\*.exe","c:\\Windows\\Performance\\*.exe","c:\\windows\\intel\\*.exe","c:\\windows\\ms\\*.exe","C:\\Windows\\dot3svc\\*.exe",
39 "C:\\Windows\\panther\\*.exe","C:\\Windows\\RemotePackages\\*.exe","C:\\Windows\\OCR\\*.exe","C:\\Windows\\appcompat\\*.exe","C:\\Windows\\apppatch\\*.exe","C:\\Windows\\addins\\*.exe",
40 "C:\\Windows\\Setup\\*.exe","C:\\Windows\\Help\\*.exe","C:\\Windows\\SKB\\*.exe","C:\\Windows\\Vss\\*.exe","C:\\Windows\\Web\\*.exe","C:\\Windows\\servicing\\*.exe","C:\\Windows\\CbsTemp\\*.exe",
41 "C:\\Windows\\Logs\\*.exe","C:\\Windows\\WaaS\\*.exe","C:\\Windows\\ShellExperiences\\*.exe","C:\\Windows\\ShellComponents\\*.exe","C:\\Windows\\PLA\\*.exe",
42 "C:\\Windows\\Migration\\*.exe","C:\\Windows\\debug\\*.exe","C:\\Windows\\Cursors\\*.exe","C:\\Windows\\Containers\\*.exe","C:\\Windows\\Boot\\*.exe","C:\\Windows\\bcastdvr\\*.exe",
43 "C:\\Windows\\assembly\\*.exe","C:\\Windows\\TextInput\\*.exe","C:\\Windows\\security\\*.exe","C:\\Windows\\schemas\\*.exe","C:\\Windows\\SchCache\\*.exe","C:\\Windows\\Resources\\*.exe",
44 "C:\\Windows\\rescache\\*.exe","C:\\Windows\\Provisioning\\*.exe","C:\\Windows\\PrintDialog\\*.exe","C:\\Windows\\PolicyDefinitions\\*.exe","C:\\Windows\\media\\*.exe",
45 "C:\\Windows\\Globalization\\*.exe","C:\\Windows\\L2Schemas\\*.exe","C:\\Windows\\LiveKernelReports\\*.exe","C:\\Windows\\ModemLogs\\*.exe","C:\\Windows\\ImmersiveControlPanel\\*.exe") and
46 not process.name : ("SpeechUXWiz.exe","SystemSettings.exe","TrustedInstaller.exe","PrintDialog.exe","MpSigStub.exe","LMS.exe","mpam-*.exe") and
47 not process.executable :
48           ("?:\\Intel\\Wireless\\WUSetupLauncher.exe",
49            "?:\\Intel\\Wireless\\Setup.exe",
50            "?:\\Intel\\Move Mouse.exe",
51            "?:\\windows\\Panther\\DiagTrackRunner.exe",
52            "?:\\Windows\\servicing\\GC64\\tzupd.exe",
53            "?:\\Users\\Public\\res\\RemoteLite.exe",
54            "?:\\Users\\Public\\IBM\\ClientSolutions\\*.exe",
55            "?:\\Users\\Public\\Documents\\syspin.exe",
56            "?:\\Users\\Public\\res\\FileWatcher.exe")
57 /* uncomment once in winlogbeat */
58 /* and not (process.code_signature.subject_name == "Microsoft Corporation" and process.code_signature.trusted == true) */
59'''
60
61
62[[rule.threat]]
63framework = "MITRE ATT&CK"
64[[rule.threat.technique]]
65id = "T1036"
66name = "Masquerading"
67reference = "https://attack.mitre.org/techniques/T1036/"
68[[rule.threat.technique.subtechnique]]
69id = "T1036.005"
70name = "Match Legitimate Name or Location"
71reference = "https://attack.mitre.org/techniques/T1036/005/"
72
73
74
75[rule.threat.tactic]
76id = "TA0005"
77name = "Defense Evasion"
78reference = "https://attack.mitre.org/tactics/TA0005/"