Detection rules › Splunk

Rubeus Kerberos Ticket Exports Through Winlogon Access

Author
Mauricio Velazco, Splunk
Source
upstream

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.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1550.003 Use Alternate Authentication Material: Pass the Ticket
Lateral MovementT1550.003 Use Alternate Authentication Material: Pass the Ticket

Event coverage

ProviderEvent IDTitle
Sysmon10ProcessAccess

Stages and Predicates

Stage 1: search

search EventCode=10 GrantedAccess=0x1f3fff SourceImage!="C:\\\\Windows\\\\system32\\\\LogonUI.exe" SourceImage!="C:\\\\Windows\\\\system32\\\\lsass.exe" SourceImage!="C:\\\\Windows\\\\system32\\\\smss.exe" SourceImage!="C:\\\\Windows\\\\system32\\\\svchost.exe" SourceImage!="C:\\\\Windows\\\\system32\\\\wbem\\\\wmiprvse.exe" TargetImage="C:\\\\Windows\\\\system32\\\\winlogon.exe"

Stage 2: stats

stats BY CallTrace, EventID, GrantedAccess, Guid, Opcode, ProcessID, SecurityID, SourceImage, SourceProcessGUID, SourceProcessId, TargetImage, TargetProcessGUID, TargetProcessId, UserID, dest, granted_access, parent_process_exec, parent_process_guid, parent_process_id, parent_process_name, parent_process_path, process_exec, process_guid, process_id, process_name, process_path, signature, signature_id, user_id, vendor_product

Stage 3: search

search

Stage 4: search

search

Stage 5: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 10 corpus 14 (splunk 14)
GrantedAccesseq
  • 0x1f3fff
SourceImagene
  • C:\\Windows\\system32\\LogonUI.exe
  • C:\\Windows\\system32\\lsass.exe
  • C:\\Windows\\system32\\smss.exe
  • C:\\Windows\\system32\\svchost.exe
  • C:\\Windows\\system32\\wbem\\wmiprvse.exe
TargetImageeq
  • C:\\Windows\\system32\\winlogon.exe