Do a virus and spyware check on your system and that USB stick immediately. Malwarebytes and also a rescue boot disk would be good to run, Avira Antivir Rescue Disc has worked well for me a few times.
Do a virus and spyware check on your system and that USB stick immediately. Malwarebytes and also a rescue boot disk would be good to run, Avira Antivir Rescue Disc has worked well for me a few times.