Techniques
Sample rules
Windows WinLogon with Public Network Connection
- source: splunk
- technicques:
- T1542.003
Description
The following analytic detects instances of Winlogon.exe, a critical Windows process, connecting to public IP addresses. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on network connections made by Winlogon.exe. Under normal circumstances, Winlogon.exe should not connect to public IPs, and such activity may indicate a compromise, such as the BlackLotus bootkit attack. This detection is significant as it highlights potential system integrity breaches. If confirmed malicious, attackers could maintain persistence, bypass security measures, and compromise the system at a fundamental level.
Detection logic
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name IN (winlogon.exe) Processes.process!=unknown by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
| `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 != 0 NOT (All_Traffic.dest IN (127.0.0.1,10.0.0.0/8,172.16.0.0/12, 192.168.0.0/16, 0:0:0:0:0:0:0:1)) by All_Traffic.process_id All_Traffic.dest All_Traffic.dest_port
| `drop_dm_object_name(All_Traffic)`
| rename dest as publicIp ]
| table dest parent_process_name process_name process_path process process_id dest_port publicIp
| `windows_winlogon_with_public_network_connection_filter`