Here is a tutorial: http://www.syschat.com/remove-antivi...ista-4308.html
Internet security is best performed by personal practice and habits. This thing can download on it's own but your choosing to run it would be questionable. $80 is a lot of money.
When in doubt about something google it....doesn't cost anything but a bit of time....but less than what you are having to deal with now.
google for this and download it and install them to see if it will also help future security issues.
superantispyware (free personal use version)
malwarebytes (free trial)