According to GHacks and other sources, FossHub was hacked. Downloads of ClassicShell and Audacity were both affected. Both Audacity and ClassicShell use FossHub as official download mirrrors. The included malware will wipe your MBR rendering the PC unbootable.
Story: http://www.ghacks.net/2016/08/03/attention-fosshub-downloads-compromised/
ClassicShell Forum post: http://www.classicshell.net/forum/viewtopic.php?f=12&t=6434