The following analytic identifies the creation or deletion of a scheduled task using schtasks.exe with flags - create or delete being passed on the command-line. This has been associated with the Dragonfly threat actor, and the SUNBURST attack against Solarwinds. This analytic replaces "Scheduled Task used in BadRabbit Ransomware".
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-02-22
- Author: Bhavin Patel, Splunk
- ID: d5af132c-7c17-439c-9d31-13d55340f36c
Kill Chain Phase
- Actions on Objectives
- CIS 3
1 2 3 4 5 6 | tstats `security_content_summariesonly` count values(Processes.process) as process values(Processes.parent_process) as parent_process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=schtasks.exe (Processes.process=*delete* OR Processes.process=*create*) by Processes.user Processes.process_name Processes.parent_process_name Processes.dest | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `scheduled_task_deleted_or_created_via_cmd_filter`
The SPL above uses the following Macros:
scheduled_task_deleted_or_created_via_cmd_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
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the
Endpoint datamodel in the
Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
Known False Positives
It is possible scripts or administrators may trigger this analytic. Filter as needed based on parent process, application.
Associated Analytic Story
- DHS Report TA18-074A
- NOBELIUM Group
- Windows Persistence Techniques
- Living Off The Land
- DarkCrystal RAT
|56.0||70||80||A schedule task process $process_name$ with create or delete 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: 6