I accidentally downloaded a antivirus program called green av, it turned out to be fake and added spyware.?

When i am browsing the web i get directed to an error page, when i know the site works, or a red box that says Reported Attack site, i know this is a firefox feature, but i disabled it, and the spelling is wrong on some of the words, and when i click on it, it redirects me to the green av site, asking me for money basically. . So im asking how do i get rid of it? Is it malware/Adware/spyware? Not sure what the difference is between the three but i need to know. Thanks.

green av is a fraud trying to get your money by pretending to be computer protection. here’s how you can delete this fake antivirus: http://www.spywarevoid.com/remove-green-av-green-av-removal.html