Virus or Botnet perhaps? If your computers turned off and unplugged they can't do anything and will give up eventually, if you need a quick removal, as it has been mentioned, go into Task Manager (CTRL + Shift + Esc) and end any process you don't need (You need explorer btw)
IF you think your getting hacked by team viewer, then your a dope, team viewer is like a program, it lets other people control your computer, you can stop it by turning of your computer, task manager, or uninstall it,