Enable controlled folder access

Applies to:

  • Windows Defender Advanced Threat Protection (Windows Defender ATP)

Controlled folder access helps you protect valuable data from malicious apps and threats, such as ransomware. It is part of Windows Defender Exploit Guard. Controlled folder access is supported on Windows Server 2019 as well as Windows 10 clients.

This topic describes how to enable Controlled folder access with the Windows Security app, Group Policy, PowerShell, and mobile device management (MDM) configuration service providers (CSPs).

Enable and audit controlled folder access

You can enable controlled folder access with the Security Center app, Group Policy, PowerShell, or MDM CSPs. You can also set the feature to audit mode. Audit mode allows you to test how the feature would work (and review events) without impacting the normal use of the machine.

Note

The Controlled folder access feature will display the state in the Windows Security app under Virus & threat protection settings. If the feature is configured with Group Policy, PowerShell, or MDM CSPs, the state will change in the Windows Security app after a restart of the device. If the feature is set to Audit mode with any of those tools, the Windows Security app will show the state as Off. See Use audit mode to evaluate Windows Defender Exploit Guard features for more details on how audit mode works.

Group Policy settings that disable local administrator list merging will override controlled folder access settings. They also override protected folders and allowed apps set by the local administrator through controlled folder access. These policies include:

Use the Windows Defender Security app to enable controlled folder access

  1. Open the Windows Security app by clicking the shield icon in the task bar or searching the start menu for Defender.

  2. Click the Virus & threat protection tile (or the shield icon on the left menu bar) and then click Ransomware protection.

  3. Set the switch for Controlled folder access to On.

Use Group Policy to enable Controlled folder access

  1. On your Group Policy management machine, open the Group Policy Management Console, right-click the Group Policy Object you want to configure and click Edit.

  2. In the Group Policy Management Editor go to Computer configuration and click Administrative templates.

  3. Expand the tree to Windows components > Windows Defender Antivirus > Windows Defender Exploit Guard > Controlled folder access.

  4. Double-click the Configure Controlled folder access setting and set the option to Enabled. In the options section you must specify one of the following:

    • Enable - Malicious and suspicious apps will not be allowed to make changes to files in protected folders. A notification will be provided in the Windows event log
    • Disable (Default) - The Controlled folder access feature will not work. All apps can make changes to files in protected folders.
    • Audit Mode - If a malicious or suspicious app attempts to make a change to a file in a protected folder, the change will be allowed but will be recorded in the Windows event log. This allows you to assess the impact of this feature on your organization.

      Screenshot of group policy option with Enabled and then Enable selected in the drop down

Important

To fully enable controlled folder access, you must set the Group Policy option to Enabled and also select Enable in the options drop-down menu.

Use PowerShell to enable controlled folder access

  1. Type powershell in the Start menu, right click Windows PowerShell and click Run as administrator.

  2. Enter the following cmdlet:

    Set-MpPreference -EnableControlledFolderAccess Enabled
    

You can enable the feature in audit mode by specifying AuditMode instead of Enabled.

Use Disabled to turn the feature off.

Use MDM CSPs to enable controlled folder access

Use the ./Vendor/MSFT/Policy/Config/Defender/GuardedFoldersList configuration service provider (CSP) to allow apps to make changes to protected folders.