Detection: Scheduled Task Deleted Or Created via CMD

Updated Date: 2026-03-26 ID: d5af132c-7c17-439c-9d31-13d55340f36c Author: Bhavin Patel, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects the creation or deletion of scheduled tasks via schtasks.exe when invoked with create or delete flags, specifically focusing on those executions where the process includes additional parameters such as /tr, /sc, or /ru. The detection uses Endpoint Detection and Response (EDR) telemetry mapped to the Endpoint data model, and filters out events originating from trusted system paths like C:\Windows\System32 or C:\Program Files. It further narrows results to cases where schtasks.exe is launched by potentially suspicious parent processes such as cmd.exe, wscript.exe, or cscript.exe, and excludes service accounts. This behavior may indicate adversary efforts to gain persistence or evade detection by manipulating scheduled tasks using scripts or command shells. If confirmed malicious, such activity could lead to unauthorized code execution or the removal of monitoring mechanisms on endpoints.

Search

 1
 2| tstats `security_content_summariesonly`
 3    count
 4    min(_time) as firstTime
 5    max(_time) as lastTime
 6FROM datamodel=Endpoint.Processes WHERE
 7
 8Processes.parent_process_name="cmd.exe"
 9Processes.process_name="schtasks.exe"
10Processes.process IN (
11    "*/create*",
12    "*-create*",
13    "*/delete*",
14    "*-delete*"
15)
16NOT Processes.process IN (
17    "* \"C:\\Program Files (x86)\\*",
18    "* \"C:\\Program Files\\*",
19    "* \"C:\\Windows\\System32\\*",
20    "* \"C:\\Windows\\SysWOW64\\*",
21    "* C:\\Program Files (x86)\\*",
22    "* C:\\Program Files\\*",
23    "* C:\\Windows\\System32\\*",
24    "* C:\\Windows\\SysWOW64\\*"
25)
26NOT Processes.user="*$"
27
28BY Processes.action Processes.dest Processes.original_file_name
29   Processes.parent_process Processes.parent_process_exec
30   Processes.parent_process_guid Processes.parent_process_id
31   Processes.parent_process_name Processes.parent_process_path
32   Processes.process Processes.process_exec Processes.process_guid
33   Processes.process_hash Processes.process_id Processes.process_integrity_level
34   Processes.process_name Processes.process_path Processes.user
35   Processes.user_id Processes.vendor_product
36
37
38| `drop_dm_object_name(Processes)`
39
40| `security_content_ctime(firstTime)`
41
42| `security_content_ctime(lastTime)`
43
44| `scheduled_task_deleted_or_created_via_cmd_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	Other	`'crowdstrike:events:sensor'`	`'crowdstrike'`
Sysmon EventID 1	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
Windows Event Log Security 4688	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
scheduled_task_deleted_or_created_via_cmd_filter	`search *`

scheduled_task_deleted_or_created_via_cmd_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1053.005	Scheduled Task	Execution

Exploitation

Installation

DE.AE

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

While it is possible for legitimate scripts or administrators to trigger this behavior, filtering can be applied based on the parent process and application to reduce false positives. Analysts should reference the provided references to understand the context and threat landscape associated with this activity.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

A parent process [$parent_process_name$] with commandline [$parent_process$] spawned a schedule task process [$process_name$] with create or delete commandline [$process$] on host [$dest$]

Risk Object	Risk Object Type	Risk Score	Threat Objects
user	user	20	process, parent_process_name
dest	system	20	process, parent_process_name

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`

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: GitHub | Version: 26