The hacker in question, Charlie Miller, achieved this feat as part of a hacking competition called PWN 2 OWN. Miller hosted a malicious Web page privately, accessed it from the MacBook Air, and then, within two minutes, was able to take full control of the machine remotely and make it do his bidding.The culprit here is apparently an undiscovered flaw in the Mac Web browser Safari, which has shown to be somewhat lacking in the security department on both the iPhone and on Windows.
Charlie won $10,000 for his troubles, and he got to keep the laptop, but as part of the deal, he was also required to keep secret about the details of exploit, so hopefully there's little chance of it getting into the wild and taking over Macs around the world.
Still, we'd recommend steering clear of Safari -- and perhaps not being so smug.
Source: Switched