The following anaytic identifies MOFComp.exe loading a MOF file. The Managed Object Format (MOF) compiler parses a file containing MOF statements and adds the classes and class instances defined in the file to the WMI repository. Typically, MOFComp.exe does not reach out to the public internet or load a MOF file from User Profile paths. A filter and consumer is typically registered in WMI. Review parallel processes and query WMI subscriptions to gather artifacts. The default path of mofcomp.exe is C:\Windows\System32\wbem.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-07-15
- Author: Michael Haag, Splunk
- ID: e59b5a73-32bf-4467-a585-452c36ae10c1
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 IN ("cmd.exe", "powershell.exe") Processes.process_name=mofcomp.exe) OR (Processes.process_name=mofcomp.exe Processes.process IN ("*\\AppData\\Local\\*","*\\Users\\Public\\*", "*\\WINDOWS\\Temp\\*")) 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)` | `windows_mof_event_triggered_execution_via_wmi_filter`
The SPL above uses the following Macros:
windows_mof_event_triggered_execution_via_wmi_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 may be present from automation based applications (SCCM), filtering may be required. In addition, break the query out based on volume of usage. Filter process names or f
Associated Analytic Story
|64.0||80||80||An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ loading a MOF file.|
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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