You may see a .cpgz file if you double-click on one of the software update .bin files on a Mac. When you double-click on the .bin file the computer tries to automatically copy the file resulting in this .cpgz file. You do not need this file. Please delete it and make sure that the trashcan is emptied before proceeding with the software update.
If you need assistance installing the update, please see the following articles:
Software Update Instructions for HERO3 Cameras