This analytic looks for the execution of
at.exe with command-line arguments utilized to create a Scheduled Task on a remote endpoint. Red Teams and adversaries alike may abuse the Task Scheduler for lateral movement and remote code execution. The
at.exe binary internally leverages the AT protocol which was deprecated starting with Windows 8 and Windows Server 2012 but may still work on previous versions of Windows. Furthermore, attackers may enable this protocol on demand by changing a sytem registry key.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint- Datasource: Splunk Add-on for Sysmon
- Last Updated: 2021-11-11
- Author: Mauricio Velazco, Splunk
- ID: 4be54858-432f-11ec-8209-3e22fbd008af
Kill Chain Phase
1 2 3 4 5 6 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=at.exe OR Processes.original_file_name=at.exe) (Processes.process=*\\\\*) by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `scheduled_task_creation_on_remote_endpoint_using_at_filter`
The SPL above uses the following Macros:
scheduled_task_creation_on_remote_endpoint_using_at_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 logs with the process name, parent process, and command-line executions from your endpoints.
Known False Positives
Administrators may create scheduled tasks on remote systems, but this activity is usually limited to a small set of hosts or users.
Associated Analytic story
|54.0||90||60||A Windows Scheduled Task was created on a remote endpoint from $dest|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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