The following analytic identifies MSIExec spawning multiple discovery commands, including spawning Cmd.exe or PowerShell.exe. Typically, child processes are not common from MSIExec other than MSIExec spawning itself.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-06-13
- Author: Michael Haag, Splunk
- ID: e9d05aa2-32f0-411b-930c-5b8ca5c4fcee
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name=msiexec.exe Processes.process_name IN ("powershell.exe","cmd.exe", "nltest.exe","ipconfig.exe","systeminfo.exe") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_msiexec_spawn_discovery_command_filter`
The SPL above uses the following Macros:
windows_msiexec_spawn_discovery_command_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
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
False positives will be present with MSIExec spawning Cmd or PowerShell. Filtering will be needed. In addition, add other known discovery processes to enhance query.
Associated Analytic Story
|35.0||70||50||An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ running different discovery commands.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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