Coral Player is a scam, but not a virus. Basically the maker's create fake torrents - usually new release or popular movies. They claim to be avi files of the movie, and usually ~ 700mb or so.
However when you get the movie, all it is, is a trailer and tells you to go download coral player. If you fall for it, it asks you to pay a small fee to use coral player but you gotta give them your credit card #, which they then charge a monthly fee ( ~ $30 USD) BUT you never get any player to download, AND the file that claims you need Coral Player to play it, isn't even a movie file at all - it's just a trailer with Coral Player ad.
They 'pad out' the file to make it roughly the size of a legitimate movie, so people will download it, I mean after all, if you saw a "movie" that was only 1.5mb would you fall for it and download it?
In short, a complete scam - if you get one of these files just delete it - anything that asks you to download a "special" movie player to play it, is a SCAM.
Personally I recommend downloading VLC - it's an open source video player. There is NO FORMAT this CANNOT PLAY. So if you open up a video file in this program and it doesn't work, it's not a real video file. (VLC also plays audio):
Never fallen for the Coral player scam or such but done research on it