Name:Remote Process Instantiation via WinRM and Winrs id:0dd296a2-4338-11ec-ba02-3e22fbd008af version:4 date:2024-09-30 author:Mauricio Velazco, Splunk status:production type:TTP Description:The following analytic detects the execution of `winrs.exe` with command-line arguments used to start a process on a remote endpoint. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions mapped to the `Processes` node of the `Endpoint` data model. This activity is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this could allow attackers to execute arbitrary code on remote systems, potentially leading to further compromise and lateral spread within the network. 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 (Processes.process_name=winrs.exe OR Processes.original_file_name=winrs.exe) (Processes.process="*-r:*" OR Processes.process="*-remote:*") 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)` | `remote_process_instantiation_via_winrm_and_winrs_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:Administrators may leverage WinRM and WinRs to start a process on remote systems, but this activity is usually limited to a small set of hosts or users. References: -https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/winrs -https://attack.mitre.org/techniques/T1021/006/ 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: - 'Active Directory Lateral Movement' asset_type:Endpoint confidence:60 impact:90 message:A process was started on a remote endpoint from $dest$ mitre_attack_id: - 'T1021' - 'T1021.006' observable: name:'dest' type:'Endpoint' - role: - 'Victim' 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:54 security_domain:endpoint
