Detect Rogue Domain Controller in Elastic Security
Adversaries may register a rogue Domain Controller to enable manipulation of Active Directory data. DCShadow is a method of manipulating Active Directory (AD) data, including objects and schemas, by registering (or reusing an inactive registration) and simulating the behavior of a DC. Once registered, a rogue DC may inject and replicate changes into AD infrastructure for any domain object, including credentials, group memberships, and SID history. Registering a rogue DC involves creating new server and nTDSDSA objects in the Configuration partition of the AD schema, which requires Administrator privileges (Domain or local DC) or the KRBTGT hash. This technique bypasses most SIEM sensors since changes are pushed directly via AD replication without touching standard audit paths. Mimikatz implements DCShadow via the lsadump::dcshadow module, requiring two concurrent sessions: one running as SYSTEM to register the rogue DC and stage changes, and one running as a domain admin to trigger the replication push.
MITRE ATT&CK
- Tactic
- Defense Evasion
- Technique
- T1207 Rogue Domain Controller
- Canonical reference
- https://attack.mitre.org/techniques/T1207/
Elastic Detection Query
any where
(
event.code == "1" and
(
process.command_line : ("*lsadump::dcshadow*", "*dcshadow /push*", "*dcshadow /start*",
"*dcshadow /domain*", "*dcshadow /object*", "*dcshadow /attribute*")
or (process.name : "mimikatz.exe" and process.command_line : "*dcshadow*")
)
) or
(
event.code == "5137" and
(
winlog.event_data.ObjectClass : "nTDSDSA"
or winlog.event_data.ObjectDN : "*NTDS Settings*"
or message : "*nTDSDSA*"
)
) or
(
event.code in ("4928", "4929") and
winlog.channel : "Security"
) or
(
event.code == "4742" and
(
winlog.event_data.ServicePrincipalNames : "*GC/*"
or winlog.event_data.ServicePrincipalNames : "*E3514235-4B06-11D1-AB04-00C04FC2DCD2*"
or message : "*E3514235-4B06-11D1-AB04-00C04FC2DCD2*"
)
)Detects DCShadow / Rogue Domain Controller (T1207) across four parallel branches using Elastic EQL: Mimikatz DCShadow process arguments (Sysmon Event 1), nTDSDSA object creation in the AD Configuration partition (Security Event 5137), AD replication source context establishment or removal (Security Events 4928/4929), and computer account modification with DC-like Global Catalog or DRSUapi SPNs (Security Event 4742).
Data Sources
Required Tables
False Positives & Tuning
- Legitimate Domain Controller promotion via Add-WindowsFeature AD-Domain-Services or dcpromo generates Events 5137, 4928, and 4929 during normal ADDS role installation — validate against change management tickets and CMDB records for known DC hostnames before escalating
- Planned AD replication topology reconfiguration by domain administrators modifying site link bridges or decommissioning replication agreements produces Events 4928 and 4929 on all DCs in affected sites
- Authorized penetration testing or purple team exercises executing Mimikatz lsadump::dcshadow in a controlled lab or staging domain — coordinate with red team to suppress known test host process events
Other platforms for T1207
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Enumerate Existing DC Registrations (Baseline / Forensic Recon)
Expected signal: Sysmon Event ID 1: powershell.exe process creation with LDAP query arguments. No directory service modification events (read-only). PowerShell ScriptBlock Log Event ID 4104 capturing the LDAP filter targeting nTDSDSA objectClass. No network connections beyond standard LDAP to port 389.
- Test 2DCShadow Stage Phase — Register Rogue DC (Mimikatz SYSTEM Session)
Expected signal: Sysmon Event ID 1: mimikatz.exe process creation under NT AUTHORITY\SYSTEM context, CommandLine containing lsadump::dcshadow. Windows Security Event ID 5137 on Domain Controllers: new nTDSDSA object created under CN=Sites in the Configuration partition. Windows Security Event ID 4742: computer account of the attacking machine modified with GC/ and DRSUapi SPNs added. Sysmon Event ID 3: RPC connections from mimikatz.exe to DC on port 135 and dynamic RPC ports.
- Test 3DCShadow Push Phase — Trigger Replication (Mimikatz Domain Admin Session)
Expected signal: Sysmon Event ID 1: mimikatz.exe process creation with lsadump::dcshadow /push argument. Windows Security Event ID 4928 on receiving Domain Controllers: replica source naming context established, showing the rogue DC as the source. Windows Security Event ID 5136 on DCs: attribute modification on the target AD object (description attribute). Sysmon Event ID 3: outbound RPC connections to legitimate DC IP addresses on dynamic ports.
- Test 4Validate Replication Topology for Rogue DC Partners
Expected signal: Sysmon Event ID 1: repadmin.exe process creation (multiple instances for each flag). No AD modification events (read-only diagnostic). The /showconn output lists all inbound and outbound replication connections — any connection referencing an unexpected computer name or GUID identifies a rogue DC that has successfully registered in the replication topology.
References (10)
- https://attack.mitre.org/techniques/T1207/
- https://www.dcshadow.com/
- https://adsecurity.org/?page_id=1821
- https://github.com/shellster/DCSYNCMonitor
- https://adds-security.blogspot.fr/2018/02/detecter-dcshadow-impossible.html
- https://msdn.microsoft.com/en-us/library/ms677626.aspx
- https://github.com/gentilkiwi/mimikatz/wiki/module-~-lsadump
- https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/directory-services-component-updates
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceprocessevents-table
- https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-5137
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