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Description

The following analytic identifies a change in an Active Directory environment that could represent evidence of the DCShadow attack. DCShadow allows an attacker who has obtained privileged access to register a rogue Domain Controller (DC). Once registered, the rogue DC may be able to inject and replicate changes in the AD infrastructure for any domain object, including credentials and keys. This technique was initially released in 2018 by security researchers Benjamin Delpy and Vincent Le Toux. Specifically, the detection will trigger when a possible rogue Domain Controller computer object is created and quickly deleted within 30 seconds or less in an Active Directory domain. This behavior was identfied by simulating the DCShadow attack with Mimikatz.

  • Type: TTP

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

  • Last Updated: 2022-10-17
  • Author: Mauricio Velazco, Splunk
  • ID: 193769d3-1e33-43a9-970e-ad4a88256cdb

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1207 Rogue Domain Controller Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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 `wineventlog_security` EventCode=5137 OR EventCode=5141 ObjectDN="*CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration*" 
| transaction ObjectDN startswith=(EventCode=5137) endswith=(EventCode=5141) 
| eval short_lived=case((duration<30),"TRUE") 
| search short_lived = TRUE 
| stats values(ObjectDN) values(signature) values(EventCode) by _time, Computer, SubjectUserName 
| `windows_ad_short_lived_server_object_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_ad_short_lived_server_object_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
  • ObjectDN
  • signature
  • SubjectUserName
  • Computer

How To Implement

To successfully implement this search, you ned to be ingesting Event codes 5137 and 5141. The Advanced Security Audit policy setting Audit Directory Services Changes within DS Access needs to be enabled. For these event codes to be generated, specific SACLs are required.

Known False Positives

Creating and deleting a server object within 30 seconds or less is unusual but not impossible in a production environment. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
64.0 80 80 Potential DCShadow Attack Detected on $Computer$

:information_source: 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

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

source | version: 1