The following analytic identifies the suspicious child process of calc.exe due to dll side loading technique to execute another executable. This technique was seen in qakbot malware that uses dll side loading technique to calc applications to load its malicious dll code. The malicious dll that abuses dll side loading technique will load the actual qakbot loader dll using regsvr32.exe application. This TTP is a good indicator of qakbot since the calc.exe will not load other child processes aside from win32calc.exe.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-10-20
- Author: Teoderick Contreras, Splunk
- ID: 295ca9ed-e97b-4520-90f7-dfb6469902e1
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 = "calc.exe") AND Processes.process_name != "win32calc.exe" by Processes.parent_process Processes.process_name Processes.process_id Processes.process_guid Processes.process Processes.user Processes.dest | `drop_dm_object_name("Processes")` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_dll_side_loading_process_child_of_calc_filter`
The SPL above uses the following Macros:
windows_dll_side-loading_process_child_of_calc_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
Associated Analytic Story
|81.0||90||90||calc.exe has a child process $process_name$ in $dest$|
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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