The following analytic leverages Windows Security EventCode 4698,
A scheduled task was created and Windows Security EventCode 4699,
A scheduled task was deleted to identify scheduled tasks created and deleted in less than 30 seconds. This behavior may represent a lateral movement attack abusing the Task Scheduler to obtain code execution. Red Teams and adversaries alike may abuse the Task Scheduler for lateral movement and remote code execution.
- Type: TTP
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2021-12-03
- Author: Mauricio Velazco, Splunk
- ID: 6fa31414-546e-11ec-adfa-acde48001122
|T1053.005||Scheduled Task||Execution, Persistence, Privilege Escalation|
Kill Chain Phase
1 2 3 4 5 6 7 `wineventlog_security` EventCode=4698 OR EventCode=4699 | xmlkv Message | transaction Task_Name startswith=(EventCode=4698) endswith=(EventCode=4699) | eval short_lived=case((duration<30),"TRUE") | search short_lived = TRUE | table _time, ComputerName, Account_Name, Command, Task_Name, short_lived | `short_lived_scheduled_task_filter`
The SPL above uses the following Macros:
Note that short_lived_scheduled_task_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
How To Implement
To successfully implement this search, you need to be ingesting Windows Security Event Logs with 4698 EventCode enabled. The Windows TA is also required.
Known False Positives
Although uncommon, legitimate applications may create and delete a Scheduled Task within 30 seconds. Filter as needed.
Associated Analytic story
|81.0||90||90||A windows scheduled task was created and deleted in 30 seconds on $ComputerName$|
source | version: 1