Access to a Sensitive LDAP Attribute

 1[metadata]
 2creation_date = "2022/11/09"
 3integration = ["system", "windows"]
 4maturity = "production"
 5min_stack_comments = "New fields added: required_fields, related_integrations, setup"
 6min_stack_version = "8.3.0"
 7updated_date = "2023/10/23"
 8
 9[rule]
10author = ["Elastic"]
11description = """
12Identify access to sensitive Active Directory object attributes that contains credentials and decryption keys such as
13unixUserPassword, ms-PKI-AccountCredentials and msPKI-CredentialRoamingTokens.
14"""
15from = "now-9m"
16index = ["winlogbeat-*", "logs-system.*", "logs-windows.*"]
17language = "eql"
18license = "Elastic License v2"
19name = "Access to a Sensitive LDAP Attribute"
20references = [
21    "https://www.mandiant.com/resources/blog/apt29-windows-credential-roaming",
22    "https://social.technet.microsoft.com/wiki/contents/articles/11483.windows-credential-roaming.aspx",
23    "https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-5136",
24]
25risk_score = 47
26rule_id = "764c9fcd-4c4c-41e6-a0c7-d6c46c2eff66"
27setup = """
28
29The 'Audit Directory Service Access' logging policy must be configured for (Success, Failure).
30Steps to implement the logging policy with Advanced Audit Configuration:

 1"""
 2severity = "medium"
 3tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Credential Access", "Tactic: Privilege Escalation", "Use Case: Active Directory Monitoring", "Data Source: Active Directory"]
 4timestamp_override = "event.ingested"
 5type = "eql"
 6
 7query = '''
 8any where event.action == "Directory Service Access" and event.code == "4662" and
 9
10  not winlog.event_data.SubjectUserSid : "S-1-5-18" and
11
12  winlog.event_data.Properties : (
13   /* unixUserPassword */
14  "*612cb747-c0e8-4f92-9221-fdd5f15b550d*",
15
16  /* ms-PKI-AccountCredentials */
17  "*b8dfa744-31dc-4ef1-ac7c-84baf7ef9da7*",
18
19  /*  ms-PKI-DPAPIMasterKeys */
20  "*b3f93023-9239-4f7c-b99c-6745d87adbc2*",
21
22  /* msPKI-CredentialRoamingTokens */
23  "*b7ff5a38-0818-42b0-8110-d3d154c97f24*"
24  ) and
25
26  /*
27   Excluding noisy AccessMasks
28   0x0 undefined and 0x100 Control Access
29   https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4662
30   */
31  not winlog.event_data.AccessMask in ("0x0", "0x100")
32'''
33
34
35[[rule.threat]]
36framework = "MITRE ATT&CK"
37[[rule.threat.technique]]
38id = "T1003"
39name = "OS Credential Dumping"
40reference = "https://attack.mitre.org/techniques/T1003/"
41
42[[rule.threat.technique]]
43id = "T1552"
44name = "Unsecured Credentials"
45reference = "https://attack.mitre.org/techniques/T1552/"
46[[rule.threat.technique.subtechnique]]
47id = "T1552.004"
48name = "Private Keys"
49reference = "https://attack.mitre.org/techniques/T1552/004/"
50
51[rule.threat.tactic]
52id = "TA0006"
53name = "Credential Access"
54reference = "https://attack.mitre.org/tactics/TA0006/"
55
56[[rule.threat]]
57framework = "MITRE ATT&CK"
58[[rule.threat.technique]]
59id = "T1078"
60name = "Valid Accounts"
61reference = "https://attack.mitre.org/techniques/T1078/"
62[[rule.threat.technique.subtechnique]]
63id = "T1078.002"
64name = "Domain Accounts"
65reference = "https://attack.mitre.org/techniques/T1078/002/"
66
67
68
69[rule.threat.tactic]
70id = "TA0004"
71name = "Privilege Escalation"
72reference = "https://attack.mitre.org/tactics/TA0004/"