How to get rid of an unknown virus? And is it a virus?

Question

Malware

When I tried to enter the browser, my Kaspersky antivirus suddenly woke up, which indicated that it had blocked the opening of some site. Having studied what he gave me, I realized that browsers are trying to connect to some left sites, but the antivirus blocks the entrance to them (I attach screenshots below). I didn’t visit any dubious sites, I downloaded only an unlicensed plugin for FL Studio, after which problems started. Even with full scans, antiviruses do not see any problems, which is extremely strange.
I apologize if the question is of a lamer nature, it's just that the situation is rather unpleasant.