HELP! When your computer is getting hacked, can the hacker type/talk to you?!?

My brother computer is acting real fishy, my brother was on his computer till it started acting up so then he decided to google "How to get rid of hackers/viruses" and then the word immediately ERASED and he retyped it, happen again and then he typed "Am I getting hacked" and it ERASED again! And then the computer itself typed in YES. So he got worried an tried to type in how to get rid of hackers again and then it erased and typed in, by itself; Shut the f*** up and turn your computer off. So now it is off... WHAT NOW?!