LoFP / although uncommon, legitimate applications may create and delete a scheduled task within 30 seconds. filter as needed.

Techniques

Sample rules

Short Lived Scheduled Task

• source: splunk
• technicques:

Description

The following analytic detects the creation and deletion of scheduled tasks within a short time frame (less than 30 seconds) using Windows Security EventCodes 4698 and 4699. This behavior is identified by analyzing Windows Security Event Logs and leveraging the Windows TA for parsing. Such activity may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this could lead to unauthorized access, data exfiltration, or execution of malicious payloads, necessitating prompt investigation and response by security analysts.

Detection logic

`wineventlog_security`
EventCode IN (4698, 4699)

| xmlkv object_attrs

| transaction TaskName dest startswith=(EventCode=4698) endswith=(EventCode=4699) maxspan=30s

| stats count min(_time) AS firstTime
              max(_time) AS lastTime
    by Command TaskName user dest RunLevel

| `security_content_ctime(firstTime)`

| `security_content_ctime(lastTime)`

| `short_lived_scheduled_task_filter`