Microsoft has added a new security tool to its Edge browser. Called Scareware Blocker, it is designed to detect and prevent attacks that fall under scareware.
Good to know: Scareware attacks use pressure to get users to do something that they should not. Common types are warnings about viruses found or that data has been leaked or accessed.
The goal of the attack is to gain access to a user’s computer system. Scareware attacks may display phone numbers that are made to look like tech support numbers. When a user calls these numbers, agents at the other end of the line try their best to gain access to the users device, for instance using remote computing.
Scareware often uses a browser’s fullscreen mode to prevent that users go back or run other searches to find out more about what is displayed on their screen.
Tip: long-pressing the ESC-key will always get you out of Fullscreen-mode.
Microsoft Edge: Scareware Blocker
Microsoft announced the new security tool in 2024. It is now available as a preview in Edge.
Here are the key points of the feature:
- Scareware Blocker needs to be enabled, at least currently while in preview.
- It complements Defender SmartScreen, which blocks known scareware pages and sites already.
- The blocker uses machine learning on the local computer to determine whether a webpage is running a Scareware attack potentially.
If Scareware Blocker’s analysis concludes that a webpage is likely running a scam attack, it is existing fullscreen mode automatically and displaying a warning to the user.

It is possible to select continue to go back, which is useful if it is a false positiv. The close page button enables users to close the page instead. All other options to close the page are also available, as fullscreen mode is no longer active thanks to the intervention of the security feature.
Users may report scareware attacks to Microsoft. This helps Defender SmartScreen “detect scareware outbreaks across multiple machines”. Users may also report false positives to Microsoft.
Microsoft admits that Scareware Blocker won’t detect every scam, but that is true for any security feature or software.
How to enable Scareware Blocker in Microsoft Edge

Note: the feature is only available in Microsoft Edge for Windows at the time of writing.
Here are the steps to enable the feature in Microsoft’s web browser:
- Open Microsoft Edge.
- Select Menu > Help > About Microsoft Edge to make sure the browser is up to date.
- Open Menu > Settings.
- Select Privacy, search, and services.
- Scroll down to the Security section on the page.
- Toggle “Scareware blocker” to enable the feature.
You can repeat the process at any time to disable the security feature again.
In Microsoft we trust!, right?