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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

ATT&CK

ID Technique Tactic
T1053.005 Scheduled Task Execution, Persistence, Privilege Escalation
Kill Chain Phase
  • Exploitation
NIST
CIS20
CVE
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` 

Macros

The SPL above uses the following Macros:

:information_source: 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 $ComputerName$

:information_source: 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

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