Winform Publish: Windows Protected your PC

Question

I distribut a WinForms App and when the user is installing a message appear on screen:
"Windows protected your PC
Microsoft Defender SmartScreen prevented an unrecognized app from starting. Running this app might put your PC at risk
"

I would like to understand what I need to do make my app reliable.
tks

Answer 1

You can apparently use an EV code-signing certificate to "buy trust" (interesting concept - one would have to say) - it is essentially a more expensive certificate with USB hardware token security and a more rigorous vetting process for the buyer (and there are further details): "Programs signed by an EV Code Signing certificate can immediately establish reputation with SmartScreen reputation services even if no prior reputation exists for that file or publisher."
Microsoft SmartScreen & Extended Validation (EV) Code Signing Certificates
https://learn.microsoft.com/en-us/archive/blogs/ie/microsoft-smartscreen-extended-validation-ev-code-signing-certificates
Similar case here:
How to avoid the “Windows Defender SmartScreen prevented an unrecognized app from starting warning”
https://stackoverflow.com/questions/48946680/how-to-avoid-the-windows-defender-smartscreen-prevented-an-unrecognized-app-fro

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Answer 2

Hello @Teemo Tang , Thanks for your answer!