The following query utilizes Windows Security EventCode 4698,
A scheduled task was created, to identify suspicious tasks registered on Windows either via schtasks.exe OR TaskService with a command to be executed with a native Windows shell (PowerShell, Cmd, Wscript, Cscript).
The search will return the first time and last time the task was registered, as well as the
Command to be executed,
Enabled, and whether it is
Hidden or not.
schtasks.exe is natively found in
The following DLL(s) are loaded when schtasks.exe or TaskService is launched -
taskschd.dll. If found loaded by another process, it is possible a scheduled task is being registered within that process context in memory.
Upon triage, identify the task scheduled source. Was it schtasks.exe or via TaskService? Review the job created and the Command to be executed. Capture any artifacts on disk and review. Identify any parallel processes within the same timeframe to identify source.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2021-04-12
- Author: Michael Haag, Splunk
- ID: 203ef0ea-9bd8-11eb-8201-acde48001122
|T1053.005||Scheduled Task||Execution, Persistence, Privilege Escalation|
|T1053||Scheduled Task/Job||Execution, Persistence, Privilege Escalation|
`wineventlog_security` EventCode=4698 | xmlkv Message | search Command IN ("*powershell.exe*", "*wscript.exe*", "*cscript.exe*", "*cmd.exe*", "*sh.exe*", "*ksh.exe*", "*zsh.exe*", "*bash.exe*", "*scrcons.exe*", "*pwsh.exe*") | stats count min(_time) as firstTime max(_time) as lastTime by dest, Task_Name, Command, Author, Enabled, Hidden | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `winevent_scheduled_task_created_to_spawn_shell_filter`
Associated Analytic Story
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.
Kill Chain Phase
- Privilege Escalation
Known False Positives
False positives are possible if legitimate applications are allowed to register tasks that call a shell to be spawned. Filter as needed based on command-line or processes that are used legitimately.
|70.0||70||100||A windows scheduled task was created (task name=$Task_Name$) on $dest$ by the following command: $Command$|
source | version: 1