Anyone who has downloaded HandBrake on Mac between [02/May/2017 14:30 UTC] and [06/May/2017 11:00 UTC] needs to verify the SHA1 / 256 sum of the file before running it.
Anyone who has installed HandBrake for Mac needs to verify their system is not infected with a Trojan. You have 50/50 chance if you’ve downloaded HandBrake during this period.”
If you have Handbrake installed on your Macs, you should check if it is compromised by this Trojan.
“Based on the information we have, you must also change all the passwords that may reside in your OSX KeyChain or any browser password stores.”