The following analytic identifies instances of the WinDBG process spawning AutoIt3. This behavior may indicate malicious activity as AutoIt3 is often used by threat actors for scripting malicious automation. The search specifically looks for instances where the parent process name is 'windbg.exe' and the process name is 'autoit3.exe' or 'autoit*.exe'. During the triage process, it is recommended to review the file path for additional artifacts that may provide further insights into the event.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2023-10-31
- Author: Michael Haag, Splunk
- ID: 7aec015b-cd69-46c3-85ed-dac152056aa4
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 7 8 9 10 11 12 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name=windbg.exe AND (Processes.process_name IN ("autoit3.exe", "autoit*.exe") OR Processes.original_file_name IN ("autoit3.exe", "autoit*.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)` | eval matches_extension=if(match(process, "\\.(au3 |a3x |exe |aut |aup)$"), "Yes", "No") | search matches_extension="Yes" | `windows_windbg_spawning_autoit3_filter`
The SPL above uses the following Macros:
windows_windbg_spawning_autoit3_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 only be present if the WinDBG process legitimately spawns AutoIt3. Filter as needed.
Associated Analytic Story
|100.0||100||100||An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$.|
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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