Short Lived Scheduled Task
Description
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
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
CIS20
CVE
Search
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`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`
Macros
The SPL above uses the following Macros:
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.
Required fields
List of fields required to use this analytic.
- _time
- dest
- ComputerName
- Account_Name
- Task_Name
- Description
- Command
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
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
81.0 | 90 | 90 | A windows scheduled task was created and deleted in 30 seconds on $ComputerName$ |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- https://attack.mitre.org/techniques/T1053/005/
- https://docs.microsoft.com/en-us/windows/win32/taskschd/about-the-task-scheduler
Test Dataset
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
source | version: 1