Detection: Windows Scheduled Task XML Built Via Console Echo

Description

The following analytic detects cmd.exe being used to write a Windows Scheduled Task XML definition to disk through the echo command. This analytic focuses on command lines that combine echo with the Task Scheduler XML namespace. This is a significant activity because legitimate software rarely assembles a task definition on the fly from the console. Browser hijackers and adware droppers do this to create a scheduled task, through schtasks.exe and the generated XML file, that periodically relaunches a copy of themselves, and then delete the XML file to hinder forensic analysis. If confirmed malicious, this could allow an attacker to establish persistence, repeatedly execute a payload and maintain control over the victim's browser.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5
 6from datamodel=Endpoint.Processes where
 7
 8(
 9    Processes.process_name=cmd.exe
10    OR
11    Processes.original_file_name=Cmd.Exe
12)
13Processes.process="*echo *"
14Processes.process="*Task version=*"
15Processes.process="*xmlns=\"http://schemas.microsoft.com/windows/*"
16
17by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
18   Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
19   Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
20   Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
21   Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
22
23
24| `drop_dm_object_name(Processes)`
25
26| `security_content_ctime(firstTime)`
27
28| `security_content_ctime(lastTime)`
29
30| `windows_scheduled_task_xml_built_via_console_echo_filter`

Data Source

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

Macros Used

Annotations

Default Configuration

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

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

False positives are not expected as building a scheduled task XML definition through echo on the command line is rare in legitimate software. Some custom installers or administrative scripts that generate task definitions this way may trigger this detection. Filter as needed based on the parent process.

Associated Analytic Story

• Living Off The Land

• Scheduled Tasks

• Browser Hijacking

Finding

Threat Objects

References

• https://learn.microsoft.com/en-us/windows/win32/taskschd/task-scheduler-schema

• https://www.gdatasoftware.com/blog/2025/11/38298-learning-about-browser-hijacking

• https://www.joesandbox.com/analysis/1965188/0/html

Detection Testing

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: 1