# Task Scheduler Operational Log

The TaskScheduler/Operational event log channel provides detailed tracing of scheduled tasks on an endpoint.

## Analysis Value

{% content-ref url="../../artifacts-by-activity/execution/command-line-options" %}
[command-line-options](https://psmths.gitbook.io/windows-forensics/artifacts-by-activity/execution/command-line-options)
{% endcontent-ref %}

{% content-ref url="../../artifacts-by-activity/execution/first-executed" %}
[first-executed](https://psmths.gitbook.io/windows-forensics/artifacts-by-activity/execution/first-executed)
{% endcontent-ref %}

{% content-ref url="../../artifacts-by-activity/execution/last-executed" %}
[last-executed](https://psmths.gitbook.io/windows-forensics/artifacts-by-activity/execution/last-executed)
{% endcontent-ref %}

{% content-ref url="../../artifacts-by-activity/execution/evidence-of-execution" %}
[evidence-of-execution](https://psmths.gitbook.io/windows-forensics/artifacts-by-activity/execution/evidence-of-execution)
{% endcontent-ref %}

{% content-ref url="../../artifacts-by-activity/execution/execution-timestamp" %}
[execution-timestamp](https://psmths.gitbook.io/windows-forensics/artifacts-by-activity/execution/execution-timestamp)
{% endcontent-ref %}

{% content-ref url="../../artifacts-by-activity/file-activity/file-path" %}
[file-path](https://psmths.gitbook.io/windows-forensics/artifacts-by-activity/file-activity/file-path)
{% endcontent-ref %}

{% content-ref url="../../artifacts-by-activity/network-activity/source-identification" %}
[source-identification](https://psmths.gitbook.io/windows-forensics/artifacts-by-activity/network-activity/source-identification)
{% endcontent-ref %}

## Operating System Availability

| Major Version | Support | Major Version | Support |
| ------------- | ------- | ------------- | ------- |
| Windows 11    | ✅       | Server 2019   | ✅       |
| Windows 10    | ✅       | Server 2016   | ✅       |
| Windows 8     | ✅       | Server 2012   | ✅       |
| Windows 7     | ✅       | Server 2008   | ✅       |
| Windows Vista | ❌       | Server 2003   | ❌       |
| Windows XP    | ❌       |               |         |

## Artifact Location(s)

* `%SystemRoot%\System32\Winevt\Logs\Microsoft-Windows-TaskScheduler%4Operational.evtx`

## Artifact Interpretation

The following event IDs are useful to hunt for persistent implants on an endpoint:

| Event ID | Description                        | Information          |
| -------- | ---------------------------------- | -------------------- |
| 106      | Scheduled Task Created             | Origin Account/User  |
| 140      | Scheduled Task Updated             | Origin Account/User  |
| 141      | Scheduled Task Deleted             | Origin Account/User  |
| 200      | Scheduled Task Executed            | Executable file path |
| 201      | Scheduled Task Execution Completed | Executable file path |

This activity is also logged in the Security channel with more granular information, as follows:

| Event ID | Description            |
| -------- | ---------------------- |
| 4698     | Scheduled Task Created |
| 4702     | Scheduled Task Updated |
| 4699     | Scheduled Task Deleted |

## Caveats

Logging for these events is disabled by default and must be enabled to provide these artifacts.

## Analysis Tips

### Deleted Scheduled Tasks

Scheduled task deletion is a rare event on Windows systems and provides an easy to query, high-fidelity indicator of suspicious activity. The following event IDs may be queried:

* `Windows-TaskScheduler\Operational Event 141: Scheduled Task Deleted`
* `Security Event 4699: Scheduled Task Deleted`

### Software Installation/Uninstallation

When applications are installed on a Windows system, they will sometimes create a scheduled task to run their update functionality, making the Task Scheduler Operational log a possible option for cross-validation of other application installation artifacts such as the `Uninstall` registry key.

### Lateral Movement through Remote Scheduled Task Installation

In the event that tasks are remotely scheduled, as is commonly seen during lateral movement attempts, this activity may be identified by observing Type 3 logons via [evtx-4624-successful-logon](https://psmths.gitbook.io/windows-forensics/artifacts-by-type/event-log-artifacts/security/evtx-4624-successful-logon "mention") events in close proximity to task creation.