ServicePrincipalNames Discovery with SetSPN

Original Source: [splunk source]
Name:ServicePrincipalNames Discovery with SetSPN
id:ae8b3efc-2d2e-11ec-8b57-acde48001122
version:5
date:2024-11-28
author:Michael Haag, Splunk
status:production
type:TTP
Description:The following analytic detects the use of `setspn.exe` to query the domain for Service Principal Names (SPNs). This detection leverages Endpoint Detection and Response (EDR) data, focusing on specific command-line arguments associated with `setspn.exe`. Monitoring this activity is crucial as it often precedes Kerberoasting or Silver Ticket attacks, which can lead to credential theft. If confirmed malicious, an attacker could use the gathered SPNs to escalate privileges or persist within the environment, posing a significant security risk.
Data_source:
  • -Sysmon EventID 1
  • -Windows Event Log Security 4688
  • -CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_setspn` (Processes.process="*-t*" AND Processes.process="*-f*") OR (Processes.process="*-q*" AND Processes.process="**/**") OR (Processes.process="*-q*") OR (Processes.process="*-s*") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`| `serviceprincipalnames_discovery_with_setspn_filter`


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:False positives may be caused by Administrators resetting SPNs or querying for SPNs. Filter as needed.
References:
  -https://docs.microsoft.com/en-us/windows/win32/ad/service-principal-names
  -https://www.ired.team/offensive-security-experiments/active-directory-kerberos-abuse/t1208-kerberoasting
  -https://strontic.github.io/xcyclopedia/library/setspn.exe-5C184D581524245DAD7A0A02B51FD2C2.html
  -https://attack.mitre.org/techniques/T1558/003/
  -https://social.technet.microsoft.com/wiki/contents/articles/717.service-principal-names-spn-setspn-syntax.aspx
  -https://web.archive.org/web/20220212163642/https://www.harmj0y.net/blog/powershell/kerberoasting-without-mimikatz/
  -https://blog.zsec.uk/paving-2-da-wholeset/
  -https://msitpros.com/?p=3113
  -https://adsecurity.org/?p=3466
drilldown_searches:
name:'View the detection results for - "$user$" and "$dest$"'
search:'%original_detection_search% | search user = "$user$" dest = "$dest$"'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
name:'View risk events for the last 7 days for - "$user$" and "$dest$"'
search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'Active Directory Discovery'
    - 'Active Directory Privilege Escalation'
    - 'Compromised Windows Host'
    - 'Active Directory Kerberos Attacks'
  asset_type:Endpoint
  confidence:100
  impact:80
  message:An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to identify service principle names.
  mitre_attack_id:
    - 'T1558.003'
  observable:
    name:'user'
    type:'User'
    - role:
      - 'Victim'
    name:'dest'
    type:'Hostname'
    - role:
      - 'Victim'
    name:'parent_process_name'
    type:'Process'
    - role:
      - 'Attacker'
    name:'process_name'
    type:'Process'
    - role:
      - 'Attacker'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'Processes.dest'
    - 'Processes.user'
    - 'Processes.parent_process_name'
    - 'Processes.parent_process'
    - 'Processes.original_file_name'
    - 'Processes.process_name'
    - 'Processes.process'
    - 'Processes.process_id'
    - 'Processes.parent_process_path'
    - 'Processes.process_path'
    - 'Processes.parent_process_id'
  risk_score:80
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1558.003/atomic_red_team/windows-sysmon_setspn.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
manual_test:None