The following analytic identifies a process performing an outbound connection on port 88 used by default by the network authentication protocol Kerberos. Typically, on a regular Windows endpoint, only the lsass.exe process is the one tasked with connecting to the Kerberos Distribution Center to obtain Kerberos tickets. Identifying an unknown process using this protocol may be evidence of an adversary abusing the Kerberos protocol.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint, Network_Traffic
- Last Updated: 2022-03-09
- Author: Mauricio Velazco, Splunk
- ID: c91a0852-9fbb-11ec-af44-acde48001122
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 7 8 9 10 | tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where Processes.process_name!=lsass.exe by _time Processes.process_id Processes.process_name Processes.dest Processes.process_path Processes.process Processes.parent_process_name | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | join process_id [ | tstats `security_content_summariesonly` count FROM datamodel=Network_Traffic.All_Traffic where All_Traffic.dest_port = 88 by All_Traffic.process_id All_Traffic.dest All_Traffic.dest_port | `drop_dm_object_name(All_Traffic)` ] | table _time dest parent_process_name process_name process_path process process_id dest_port | `unknown_process_using_the_kerberos_protocol_filter`
The SPL above uses the following Macros:
unknown_process_using_the_kerberos_protocol_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the
Processes node of the
Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known False Positives
Custom applications may leverage the Kerberos protocol. Filter as needed.
Associated Analytic Story
|36.0||60||60||Unknown process $process_name$ using the kerberos protocol detected on host $dest$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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