This one is indeed very strange, because in my experience SpyHunter4 is really the best for this. If you have paid for it you can contact the technicians there to access your computer remotely.

There are two more things that you can do yourself.

1. Go to Network Connections, select your internet adapter, select properties and open the IP4 line. After you do it look for the DNS line. If it has any numbers in it set them all to zeroes or click to obtain them automatically.

2. In Chrome open the settings and look for Users. Use the create new user button to create a new user, then delete the old one you were using. Also, again in settings, select the Manage Search Engines and remove MySite123 (or other suspicious search engines) from there.

It may be entirely possible that Mysites123 is already removed from your PC and you only need to adjust back the settings that it changed.

Please, let me know if these work for you and specifically which one fixed your problem.