The creators of media transcoding program HandBrake have issued a statement warning that certain downloads of the installer for the Mac version of the app may contain a Trojan virus.
Downloading the app between May 2 (14:30 UTC) and May 6 (11:00 UTC) from the “download.handbrake.fr” mirror means you have a 50-percent chance of being infected with the Trojan. More here.