Access to a Sensitive LDAP Attributeedit
Identify access to sensitive Active Directory object attributes that contains credentials and decryption keys such as unixUserPassword, ms-PKI-AccountCredentials and msPKI-CredentialRoamingTokens.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-system.*
- logs-windows.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Credential Access
- Active Directory
Version: 2
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guideedit
The 'Audit Directory Service Changes' logging policy must be configured for (Success, Failure). Steps to implement the logging policy with Advanced Audit Configuration: ``` Computer Configuration > Policies > Windows Settings > Security Settings > Advanced Audit Policies Configuration > Audit Policies > DS Access > Audit Directory Service Changes (Success,Failure) ```
Rule queryedit
any where event.action == "Directory Service Access" and event.code == "4662" and
not winlog.event_data.SubjectUserSid : "S-1-5-18" and
winlog.event_data.Properties : (
/* unixUserPassword */
"*612cb747-c0e8-4f92-9221-fdd5f15b550d*",
/* ms-PKI-AccountCredentials */
"*b8dfa744-31dc-4ef1-ac7c-84baf7ef9da7*",
/* ms-PKI-DPAPIMasterKeys */
"*b3f93023-9239-4f7c-b99c-6745d87adbc2*",
/* msPKI-CredentialRoamingTokens */
"*b7ff5a38-0818-42b0-8110-d3d154c97f24*"
) and
/*
Excluding noisy AccessMasks
0x0 undefined and 0x100 Control Access
https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4662
*/
not winlog.event_data.AccessMask in ("0x0", "0x100")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
-
Technique:
- Name: OS Credential Dumping
- ID: T1003
- Reference URL: https://attack.mitre.org/techniques/T1003/