They repeatedly guessed the password until they got in.
Usually done using a script to iterate through thousands of combinations after a common password dictionary search. Which means Apple does a terrible job of rate-limiting failed password attempts (or whatever service was hacked).
This message has been modified
Originally posted on Sep 2, 2014 at 9:14:29am
Message modified by supertux on Sep 2, 2014 at 9:15:03am
Message modified by supertux on Sep 2, 2014 at 9:16:21am