It's happend to me, too, with another project from another dev. You (
ChrisHaze) were either redirected or got a bad download. Refreshing the download site and redownloading the file solves the problem in most cases. The redirection/bad download can have a few reasons. Two, that I know of are either malware on your system redirecting you or, and in my personal expierence it's more likely, you got redirected because of an invasive "ad", that would install malware. As I said, best to redownload the file and check, if it's the correct one then and definitely delete the other crap.