Name:Rubeus Kerberos Ticket Exports Through Winlogon Access id:5ed8c50a-8869-11ec-876f-acde48001122 version:5 date:2024-09-30 author:Mauricio Velazco, Splunk status:production type:TTP Description:The following analytic detects a process accessing the winlogon.exe system process, indicative of the Rubeus tool attempting to export Kerberos tickets from memory. This detection leverages Sysmon EventCode 10 logs, focusing on processes obtaining a handle to winlogon.exe with specific access rights. This activity is significant as it often precedes pass-the-ticket attacks, where adversaries use stolen Kerberos tickets to move laterally within an environment. If confirmed malicious, this could allow attackers to bypass normal access controls, escalate privileges, and persist within the network, posing a severe security risk. Data_source:
-Sysmon EventID 10
search:`sysmon` EventCode=10 TargetImage=C:\\Windows\\system32\\winlogon.exe (GrantedAccess=0x1f3fff) (SourceImage!=C:\\Windows\\system32\\svchost.exe AND SourceImage!=C:\\Windows\\system32\\lsass.exe AND SourceImage!=C:\\Windows\\system32\\LogonUI.exe AND SourceImage!=C:\\Windows\\system32\\smss.exe AND SourceImage!=C:\\Windows\\system32\\wbem\\wmiprvse.exe) | stats count min(_time) as firstTime max(_time) as lastTime by dest, SourceImage, SourceProcessId, TargetImage, TargetProcessId, EventCode, GrantedAccess | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)` | `rubeus_kerberos_ticket_exports_through_winlogon_access_filter`
how_to_implement:This search needs Sysmon Logs and a sysmon configuration, which includes EventCode 10. This search uses an input macro named `sysmon`. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Windows Sysmon logs. Replace the macro definition with configurations for your Splunk environment. known_false_positives:Legitimate applications may obtain a handle for winlogon.exe. Filter as needed References: -https://github.com/GhostPack/Rubeus -https://web.archive.org/web/20210725005734/http://www.harmj0y.net/blog/redteaming/from-kekeo-to-rubeus/ -https://attack.mitre.org/techniques/T1550/003/ drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") 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: - 'CISA AA23-347A' - 'Active Directory Kerberos Attacks' - 'BlackSuit Ransomware' asset_type:Endpoint confidence:60 impact:60 message:Winlogon.exe was accessed by $SourceImage$ on $dest$ mitre_attack_id: - 'T1550' - 'T1550.003' observable: name:'dest' type:'Endpoint' - role: - 'Victim' name:'TargetImage' type:'Process' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'EventCode' - 'TargetImage' - 'CallTrace' - 'dest' - 'TargetProcessId' - 'SourceImage' - 'SourceProcessId' risk_score:36 security_domain:endpoint
