a quick google of vizvaz.com has the first entry as vizvaz.com a dynamic dns service, followed by several pages of "how to remove vizvaz.com" type sites from domains I've never heard of, including several on wordpress blogs - I didn't click on any of them, because sometimes these sites that claim to have removal instructions are just as bad.
a google of "vizvaz.com site:mcafee.com" list 4 articles from mcafee.com, listing a backdoor and a downloader:
BackDoor-DKI.gen.am and Downloader-CMJ.gen.e!50C0B9ED1E55
Exit Safari and run your favorite anti-virus software. This definitely malware, while a *nix systems like OS X can't replicate a virus, they certainly can run malware, trojans, downloaders and backdoors.
If you are running Windows, it could be hiding in the registry or several other places besides Safari settings. I'm unclear as to your system setup, as you have a macbook pro listed, but also show both the Windows and Mac categories in your original post.
It may be as easy as resetting your homepage to google.com and your default search engine to Google on the General Tab in Safari Preferences, it's hard to tell from here.