Set up and use Microsoft Defender SmartScreen on individual devices

Applies to:

  • Windows 10, version 1703
  • Windows 10 Mobile
  • Microsoft Edge

Microsoft Defender SmartScreen helps to protect users if they try to visit sites previously reported as phishing or malware websites, or if a user tries to download potentially malicious files.

How users can use Windows Security to set up Microsoft Defender SmartScreen

Starting with Windows 10, version 1703, users can use Windows Security to set up Microsoft Defender SmartScreen for an individual device; unless an administrator has used Group Policy or Microsoft Intune to prevent it.

Note

If any of the following settings are managed through Group Policy or mobile device management (MDM) settings, it appears as unavailable to the employee.

To use Windows Security to set up Microsoft Defender SmartScreen on a device

  1. Open the Windows Security app, and then select App & browser control > Reputation-based protection settings.

  2. In the Reputation-based protection screen, choose from the following options:

    • In the Check apps and files area:

      • On. Warns users that the apps and files being downloaded from the web are potentially dangerous but allows the action to continue.

      • Off. Turns off Microsoft Defender SmartScreen, so a user isn't alerted or stopped from downloading potentially malicious apps and files.

    • In the Microsoft Defender SmartScreen for Microsoft Edge area:

      • On. Warns users that sites and downloads are potentially dangerous but allows the action to continue while running in Microsoft Edge.

      • Off. Turns off Microsoft Defender SmartScreen, so a user isn't alerted or stopped from downloading potentially malicious apps and files.

    • In the Potentially unwanted app blocking area:

      • On. Turns on both the 'Block apps' and 'Block downloads settings. To learn more, see How Microsoft identifies malware and potentially unwanted applications.

        • Block apps. This setting will prevent new apps from installing on the device and warn users of apps that are existing on the device.

        • Block downloads. This setting will alert users and stop the downloads of apps in the Microsoft Edge browser (based on Chromium).

      • Off. Turns off Potentially unwanted app blocking, so a user isn't alerted or stopped from downloading or installing potentially unwanted apps.

    • In the Microsoft Defender SmartScreen from Microsoft Store apps area:

      • On. Warns users that the sites and downloads used by Microsoft Store apps are potentially dangerous but allows the action to continue.

      • Off. Turns off Microsoft Defender SmartScreen, so a user isn't alerted or stopped from visiting sites or from downloading potentially malicious apps and files.

        Windows Security, Microsoft Defender SmartScreen controls

How Microsoft Defender SmartScreen works when a user tries to run an app

Microsoft Defender SmartScreen checks the reputation of any web-based app the first time it's run from the Internet, checking digital signatures and other factors against a Microsoft-maintained service. If an app has no reputation or is known to be malicious, Microsoft Defender SmartScreen can warn the user or block the app from running entirely, depending on how you've configured the feature to run in your organization.

By default, users can bypass Microsoft Defender SmartScreen protection, letting them run legitimate apps after accepting a warning message prompt. You can also use Group Policy or Microsoft Intune to block your employees from using unrecognized apps, or to entirely turn off Microsoft Defender SmartScreen (not recommended).

How users can report websites as safe or unsafe

Microsoft Defender SmartScreen can be configured to warn users from going to a potentially dangerous site. Users can then choose to report a website as safe from the warning message or as unsafe from within Microsoft Edge and Internet Explorer 11.

To report a website as safe from the warning message

  • On the warning screen for the site, click More Information, and then click Report that this site does not contain threats. The site info is sent to the Microsoft feedback site, which provides further instructions.

To report a website as unsafe from Microsoft Edge

  • If a site seems potentially dangerous, users can report it to Microsoft by clicking More (...), clicking Send feedback, and then clicking Report unsafe site.

To report a website as unsafe from Internet Explorer 11

  • If a site seems potentially dangerous, users can report it to Microsoft by clicking on the Tools menu, clicking Windows Defender SmartScreen, and then clicking Report unsafe website.

Note

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