Windows AD Replication Service Traffic
THIS IS A EXPERIMENTAL DETECTION
This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.
Description
The following analytic identifies unexpected Active Directory replication traffic from non-domain controller sources. It leverages data from the Network Traffic datamodel, specifically looking for applications related to AD replication. This activity is significant because AD replication traffic should typically only occur between domain controllers. Detection of such traffic from other sources may indicate malicious activities like DCSync or DCShadow, which are used for credential dumping. If confirmed malicious, this could allow attackers to exfiltrate sensitive credentials, leading to unauthorized access and potential domain-wide compromise.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Network_Traffic
- Last Updated: 2024-05-19
- Author: Steven Dick
- ID: c6e24183-a5f4-4b2a-ad01-2eb456d09b67
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 13
CVE
Search
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| tstats `security_content_summariesonly` count values(All_Traffic.transport) as transport values(All_Traffic.user) as user values(All_Traffic.src_category) as src_category values(All_Traffic.dest_category) as dest_category min(_time) as firstTime max(_time) as lastTime from datamodel=Network_Traffic where All_Traffic.app IN ("ms-dc-replication","*drsr*","ad drs") by All_Traffic.src All_Traffic.dest All_Traffic.app
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `drop_dm_object_name("All_Traffic")`
| `windows_ad_replication_service_traffic_filter`
Macros
The SPL above uses the following Macros:
windows_ad_replication_service_traffic_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.
- All_Traffic.src
- All_Traffic.dest
- All_Traffic.app
How To Implement
To successfully implement this search, you need to be ingesting application aware firewall or proxy logs into the Network Datamodel. Categorize all known domain controller Assets servers with an appropriate category for filtering.
Known False Positives
New domain controllers or certian scripts run by administrators.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
100.0 | 100 | 100 | Active Directory Replication Traffic from Unknown Source - $src$ |
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://adsecurity.org/?p=1729
- https://attack.mitre.org/techniques/T1003/006/
- https://attack.mitre.org/techniques/T1207/
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: 2