Windows WinDBG Spawning AutoIt3
Description
The following analytic identifies instances of the WinDBG process spawning AutoIt3. This behavior is detected by monitoring endpoint telemetry for processes where 'windbg.exe' is the parent process and 'autoit3.exe' or similar is the child process. This activity is significant because AutoIt3 is frequently used by threat actors for scripting malicious automation, potentially indicating an ongoing attack. If confirmed malicious, this could allow attackers to automate tasks, execute arbitrary code, and further compromise the system, leading to data exfiltration or additional malware deployment.
Query · spl
| 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.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product | `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`
Implementation guide
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.
Analyst notes
Known false positives: False positives will only be present if the WinDBG process legitimately spawns AutoIt3. Filter as needed.