Yes you have been hijacked by malware, I would suggest the following to find and fix.
Download and run
ComboFix from here
A guide and tutorial on using ComboFix
Download and run Malwarebytes from here
Malwarebytes.org
after these run your other malware programs reinstall and update your antivirus programs this should get it.
You could have been hit like I was last week by a drive by downloading.
Good luck.