Evaluate controlled folder access
The improved Microsoft 365 security center is now available in public preview. This new experience brings Defender for Endpoint, Defender for Office 365, Microsoft 365 Defender, and more into the Microsoft 365 security center. Learn what's new. This topic might apply to both Microsoft Defender for Endpoint and Microsoft 365 Defender. Refer to the Applies To section and look for specific call outs in this article where there might be differences.
Controlled folder access is a feature that helps protect your documents and files from modification by suspicious or malicious apps. Controlled folder access is supported on Windows Server 2019 and Windows 10 clients.
It is especially useful in helping protect against ransomware that attempts to encrypt your files and hold them hostage.
This article helps you evaluate controlled folder access. It explains how to enable audit mode so you can test the feature directly in your organization.
You can also visit the Microsoft Defender for Endpoint demo scenario website at demo.wd.microsoft.com to confirm the feature is working and see how it works.
Use audit mode to measure impact
Enable the controlled folder access in audit mode to see a record of what would have happened if it was fully enabled. Test how the feature will work in your organization to ensure it doesn't affect your line-of-business apps. You can also get an idea of how many suspicious file modification attempts generally occur over a certain period of time.
To enable audit mode, use the following PowerShell cmdlet:
Set-MpPreference -EnableControlledFolderAccess AuditMode
If you want to fully audit how controlled folder access will work in your organization, you'll need to use a management tool to deploy this setting to devices in your network(s). You can also use Group Policy, Intune, mobile device management (MDM), or Microsoft Endpoint Manager to configure and deploy the setting, as described in the main controlled folder access topic.
Review controlled folder access events in Windows Event Viewer
The following controlled folder access events appear in Windows Event Viewer under Microsoft/Windows/Windows Defender/Operational folder.
|5007||Event when settings are changed|
|1124||Audited controlled folder access event|
|1123||Blocked controlled folder access event|
You can configure a Windows Event Forwarding subscription to collect the logs centrally.
Customize protected folders and apps
During your evaluation, you may wish to add to the list of protected folders, or allow certain apps to modify files.
See Protect important folders with controlled folder access for configuring the feature with management tools, including Group Policy, PowerShell, and MDM configuration service providers (CSPs).