Windows DnsAdmins New Member Added

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Description

The following analytic detects the addition of a new member to the DnsAdmins group in Active Directory by leveraging Event ID 4732. This detection uses security event logs to identify changes to this high-privilege group. Monitoring this activity is crucial because members of the DnsAdmins group can manage the DNS service, often running on Domain Controllers, and potentially execute malicious code with SYSTEM privileges. If confirmed malicious, this activity could allow an attacker to escalate privileges and gain control over critical domain services, posing a significant security risk.

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2024-05-29
• Author: Mauricio Velazco, Splunk
• ID: 27e600aa-77f8-4614-bc80-2662a67e2f48

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1098	Account Manipulation	Persistence, Privilege Escalation

Kill Chain Phase

• Installation
• Exploitation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

 `wineventlog_security` EventCode=4732 TargetUserName=DnsAdmins 
| stats min(_time) as firstTime max(_time) as lastTime values(TargetUserName) as target_users_added values(user) as user by  dest src_user 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_dnsadmins_new_member_added_filter`

Macros

The SPL above uses the following Macros:

• security_content_ctime
• wineventlog_security

windows_dnsadmins_new_member_added_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

• _time
• EventCode
• TargetUserName
• SubjectUserName
• Computer
• MemberSid
• TargetUserName

How To Implement

To successfully implement this search, Domain Controller events need to be ingested. The Advanced Security Audit policy setting Audit Security Group Management within Account Management needs to be enabled.

Known False Positives

New members can be added to the DnsAdmins group as part of legitimate administrative tasks. Filter as needed.

Associated Analytic Story

• Active Directory Privilege Escalation

RBA

Risk Score	Impact	Confidence	Message
40.0	80	50	A new member $user$ added to the DnsAdmins group by $src_user$

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://attack.mitre.org/techniques/T1098/
• https://www.ired.team/offensive-security-experiments/active-directory-kerberos-abuse/from-dnsadmins-to-system-to-domain-compromise
• https://www.hackingarticles.in/windows-privilege-escalation-dnsadmins-to-domainadmin/
• https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4732

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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