
Miller walked away with the US$10,000 prize put up by the organisers, along with the MacBook Air he hacked.
No one was able to hack into any of the machines by attacking them over the network on the first day of the contest.
But Miller succeeded when the organisers allowed hackers to direct human operators of the three machines to visit websites and open emails.
Miller's exploit code was on a website and the Mac fell within two minutes. He was only able to use software preinstalled on the Mac, so experts assume that the vulnerability must lay with Apple's Safari browser.
However, Miller signed a non-disclosure agreement which means that the exploit will not be made public until Apple has been informed.
At the time of posting, the other two machines remain intact.