Scheduled Task Creation on Remote Endpoint using At
Description
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
- Last Updated: 2021-11-11
- Author: Mauricio Velazco, Splunk
- ID: 4be54858-432f-11ec-8209-3e22fbd008af
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
CIS20
CVE
Search
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| 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`
Macros
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.
Supported Add-on (TA)
List of Splunk Add-on’s tested to work with the analytic.
Required fields
List of fields required to use this analytic.
- _time
- Processes.dest
- Processes.user
- Processes.parent_process_name
- Processes.parent_process
- Processes.original_file_name
- Processes.process_name
- Processes.process
- Processes.process_id
- Processes.parent_process_path
- Processes.process_path
- Processes.parent_process_id
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
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
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.
Reference
- https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/at
- https://docs.microsoft.com/en-us/windows/win32/cimwin32prov/win32-scheduledjob?redirectedfrom=MSDN
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