Potential ADIDNS Poisoning via Wildcard Record Creationedit
Active Directory Integrated DNS (ADIDNS) is one of the core components of AD DS, leveraging AD’s access control and replication to maintain domain consistency. It stores DNS zones as AD objects, a feature that, while robust, introduces some security issues, such as wildcard records, mainly because of the default permission (Any authenticated users) to create DNS-named records. Attackers can create wildcard records to redirect traffic that doesn’t explicitly match records contained in the zone, becoming the Man-in-the-Middle and being able to abuse DNS similarly to LLMNR/NBNS spoofing.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-system.*
- logs-windows.*
Severity: high
Risk score: 73
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Credential Access
- Data Source: Active Directory
- Use Case: Active Directory Monitoring
Version: 1
Rule authors:
- Elastic
Rule license: Elastic License v2
Setupedit
Setup
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)
The above policy does not cover the target object by default (we still need it to be configured to generate events), so we need to set up an AuditRule using https://github.com/OTRF/Set-AuditRule.
Set-AuditRule -AdObjectPath 'AD:\CN=MicrosoftDNS,DC=DomainDNSZones,DC=Domain,DC=com' -WellKnownSidType WorldSid -Rights CreateChild -InheritanceFlags Descendents -AttributeGUID e0fa1e8c-9b45-11d0-afdd-00c04fd930c9 -AuditFlags Success
Rule queryedit
any where host.os.type == "windows" and event.action == "Directory Service Changes" and
event.code == "5137" and startsWith(winlog.event_data.ObjectDN, "DC=*,")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
-
Technique:
- Name: Adversary-in-the-Middle
- ID: T1557
- Reference URL: https://attack.mitre.org/techniques/T1557/