Techniques
Sample rules
Remote Desktop Network Traffic
- source: splunk
- technicques:
- T1021.001
- T1021
Description
The following analytic detects unusual Remote Desktop Protocol (RDP) traffic on TCP/3389, the default RDP port. It identifies this activity by filtering out traffic from known RDP sources and destinations, focusing on atypical RDP connections within the network. This detection is crucial for a Security Operations Center (SOC) as unauthorized RDP access can indicate an attacker’s attempt to gain control over networked systems, potentially leading to data theft, ransomware deployment, or further network compromise. The impact of such unauthorized access can be significant, ranging from data breaches to complete system and network control loss.
Detection logic
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Network_Traffic where All_Traffic.dest_port=3389 AND All_Traffic.dest_category!=common_rdp_destination AND All_Traffic.src_category!=common_rdp_source AND All_Traffic.action="allowed" by All_Traffic.src All_Traffic.dest All_Traffic.dest_port
| `drop_dm_object_name("All_Traffic")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `remote_desktop_network_traffic_filter`
Remote Desktop Process Running On System
- source: splunk
- technicques:
- T1021.001
- T1021
Description
This search looks for the remote desktop process mstsc.exe running on systems upon which it doesn’t typically run. This is accomplished by filtering out all systems that are noted in the common_rdp_source category in the Assets and Identity framework.
Detection logic
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process=*mstsc.exe AND Processes.dest_category!=common_rdp_source by Processes.dest Processes.user Processes.process
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `drop_dm_object_name(Processes)`
| `remote_desktop_process_running_on_system_filter`