The following analytic utilizes a Splunk query to pinpoint potential threats by monitoring the 'schtasks.exe' command-line usage. This particular command, especially when used in tandem with 'shutdown' and '/create' flags, can suggest an adversarial force intending to schedule unwarranted system reboots. The query focuses on endpoint process data and retrieves details such as the process name, the parent process name, the destination, and the user involved. Essential to the investigation are the earliest and latest timestamps of these events, providing an activity timeline. Data such as the targeted host and initiating user offer valuable context for analyst.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2020-12-07
- Author: Bhavin Patel, Splunk
- ID: 1297fb80-f42a-4b4a-9c8a-88c066437cf6
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 | tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=schtasks.exe Processes.process="*shutdown*" Processes.process="*/create *" by Processes.process_name Processes.parent_process_name Processes.dest Processes.user | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `schtasks_used_for_forcing_a_reboot_filter`
The SPL above uses the following Macros:
schtasks_used_for_forcing_a_reboot_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
This analytic may also capture legitimate administrative activities such as system updates or maintenance tasks, which can be classified as false positives. Filter as needed.
Associated Analytic Story
|56.0||70||80||A schedule task process $process_name$ with force reboot commandline $process$ in host $dest$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 4