Thank you for your responses, but I solved the problem by myself. Firstly, I tried some solutions that helped others (I found them by googling the problem), mainly removing some extensions in browsers, which were masked to look like real ones, and some other stuff, yet, I would still get those...
UPDATE: It was a trojan; when you read what it states, it's - ahoravideo-endpoint.xyz - Ahoravideo-endpoint.com is a Command & Control (C&C) server for VenomSoftX malware, a dangerous JavaScript-based RAT (remote access trojan), and a cryptocurrency hijacker. VenomSoftX focuses on stealing...
Ok, since upgrading my OS from Windows 10 to Windows 11, I experience this kind of problem from time to time. Randomly, I will get a couple of the same windows that pops up saying how I need to resolve DNS name. Tried to reset my IP address, flush DNS, renew, tried also to set Google DNS...