This analytic looks for the execution of
powershell.exe with arguments utilized to start a process on a remote endpoint by abusing the WinRM protocol. Specifically, this search looks for the abuse of the
Invoke-Command commandlet. Red Teams and adversaries alike may abuse WinRM and
powershell.exe for lateral movement and remote code execution.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint- Datasource: Splunk Add-on for Sysmon
- Last Updated: 2021-11-16
- Author: Mauricio Velazco, Splunk
- ID: ba24cda8-4716-11ec-8009-3e22fbd008af
Kill Chain Phase
1 2 3 4 5 6 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_powershell` (Processes.process="*Invoke-Command*" AND Processes.process="*-ComputerName*") 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_powershell_filter`
The SPL above uses the following Macros:
remote_process_instantiation_via_winrm_and_powershell_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
How To Implement
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints.
Known False Positives
Administrators may leverage WinRM and
Invoke-Command to start a process on remote systems for system administration or automation use cases. However, this activity is usually limited to a small set of hosts or users.
Associated Analytic story
|45.0||90||50||A process was started on a remote endpoint from $dest by abusing WinRM using PowerShell.exe|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1