MPlayerX began to be associated with malware about two years ago, or possibly even longer. The official installer started to include the IronCore adware. When run in a virtual machine, it installed nothing but MPlayer X. When opened on a real system, however, it would install the. IronCore. adware, MacKeeper, and MegaBackup. The installer still exhibited the same analysis avoidance behavior, this time installing IronCore, Mac.Keeper and ZipCloud. If you feel that you dont want to be running that you must use an. installer, get it from the Mac App Store instead of the.”]
Source: https://blog.malwarebytes.com/puppum/2016/09/pup-friday-mplayerx/