What is this

It might well be phishing emails/intrusions coming from that internet domain or from other domains run by whoever is hosting that site.

Denis

walleyeblugill said:

What caused this ?

That is Microsoft Defender SmartScreen in action.

Microsoft said:

Microsoft Defender SmartScreen determines whether a site is potentially malicious by:

• Analyzing visited webpages for indications of suspicious behavior.
• Checking the visited sites against a dynamic record of reported phishing sites.

If Microsoft Defender SmartScreen determines that a page is malicious, it will show a warning page to notify the user that that site is reported as unsafe.

https://docs.microsoft.com/en-us/deployedge/microsoft-edge-security-smartscreen


Note that the Soundestlink url in your screenshot is a redirection site, similar to TinyURL. It would more likely be that it is the site you would be redirected to that has been flagged as unsafe rather than Soundestlink, either because of unsafe code on that other site, or that other users have reported it as unsafe.