First of all, disable your network connection. If your machine is disconnected from the internet than it probably won't be affected by any virus badly. You will probably have to do this manually. Unplug the ethernet cable in your machine or the WiFi card. You have probably been infected by a Remote Administration Tool. Delete anything downloaded on the machine recently and let the antivirus software scan. I would back up your core information, in case the "hacker" (probably what hackers call a "script kiddie") decides to do something more serious, like installing ransomware or deleting your documents. If you don't have it stopped by the scan, you can either root around in Linux or just re-install your OS replacing with backup information. Make sure, though, to back-up all your games, installed and downloaded paid software, and personal documents. Once you've reached a solution you can reconnect your machine to the internet. I hope this helps!