seems like that is definitely a virus/malware problem. What antivirus are you using, and is it up to date? Sometimes viruses can deactivate the antivirus software in place.

Try downloading another antivirus and scheduling either a boot time scan or do one yourself in safe mode.

I would recommend Avast! but for quickly identifying a problem, try Malwarebytes Antimalware - its a small download, and getting virus definitions should be relatively quick...