It looks like Microsoft is testing a new Microsoft Defender Windows and intends to release it on the insiders channel.
The user Aggiornamenti Lumia published on Twitter a screenshot of the home screen of the new protection program. The application was codenamed GibraltarApp and so all the files in the internal version were named, whether they were .exe or .dlls.
The application is currently a WPF (Windows Presentation Foundation) and uses XAML and WebView2. It will replace the current Inbox application in Windows 11.
It is claimed to offer "simple, seamless and personalized protection" to users and is expected to be released to Windows Insiders in the near future.
We are waiting and seeing her up close.