On February 20th, the Linux Mint website was hacked and a download link for an altered version of Linux Mint 17.3 Cinnamon containing a backdoor was placed on the site. The hackers also appear to have dumped the entire forum database and forum php code and have this information for sale on the Dark Net.

http://www.zdnet.com/article/linux-mint-website-hacked-malicious-backdoor-version/

The Linux Mint site is currently offline pending recovery and updating. If you downloaded and burned to disc an ISO of Linux Mint 17.3 Cinnamon from the site's standard download option (as opposed to a torrent or direct HTTP download) on February 20th, set a glass of tea on it or use it as a suncatcher...

DR