Detection: Unknown Process Using The Kerberos Protocol

Updated Date: 2026-02-25 ID: c91a0852-9fbb-11ec-af44-acde48001122 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies a non-lsass.exe process making an outbound connection on port 88, which is typically used by the Kerberos authentication protocol. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and network traffic logs. This activity is significant because, under normal circumstances, only the lsass.exe process should interact with the Kerberos Distribution Center. If confirmed malicious, this behavior could indicate an adversary attempting to abuse the Kerberos protocol, potentially leading to unauthorized access or lateral movement within the network.

Search

 1
 2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes
 3  WHERE Processes.process_name!=lsass.exe
 4  BY _time Processes.action Processes.dest
 5     Processes.original_file_name Processes.parent_process Processes.parent_process_exec
 6     Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name
 7     Processes.parent_process_path Processes.process Processes.process_exec
 8     Processes.process_guid Processes.process_hash Processes.process_id
 9     Processes.process_integrity_level Processes.process_name Processes.process_path
10     Processes.user Processes.user_id Processes.vendor_product
11
12| `drop_dm_object_name(Processes)`
13
14| `security_content_ctime(firstTime)`
15
16| `security_content_ctime(lastTime)`
17
18| join  process_id dest [
19
20| tstats `security_content_summariesonly` count FROM datamodel=Network_Traffic.All_Traffic
21  WHERE All_Traffic.dest_port = 88
22  BY All_Traffic.action All_Traffic.app All_Traffic.bytes
23     All_Traffic.bytes_in All_Traffic.bytes_out All_Traffic.dest
24     All_Traffic.dest_ip All_Traffic.dest_port All_Traffic.dvc
25     All_Traffic.protocol All_Traffic.protocol_version All_Traffic.src
26     All_Traffic.src_ip All_Traffic.src_port All_Traffic.transport
27     All_Traffic.user All_Traffic.vendor_product All_Traffic.direction
28     All_Traffic.process_id
29
30| `drop_dm_object_name(All_Traffic)`
31
32| rename src as dest ]
33
34| table _time dest parent_process_name process_name process_path process process_id dest_port
35
36| `unknown_process_using_the_kerberos_protocol_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 1	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
Sysmon EventID 3	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
unknown_process_using_the_kerberos_protocol_filter	`search *`

unknown_process_using_the_kerberos_protocol_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1550	Use Alternate Authentication Material	Defense Evasion

Exploitation

DE.CM

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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

Risk Based Analytics (RBA)

Risk Message:

Unknown process $process_name$ using the kerberos protocol detected on host $dest$

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	36	No Threat Objects

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`WinEventLog:Security`	`WinEventLog`
Integration	✅ Passing	Dataset	`WinEventLog:Security`	`WinEventLog`

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: GitHub | Version: 9