Reports suggest that both Facebook and Apple employees—and likely others, including Twitter—visited an infected Web site laden with malware, which exploited a vulnerability in Java. Now the cause has been identified, here's what you can do.
The root cause is reportedly one iPhone development Web site that became infected with malware, which was then able to dump its malicious payload on vulnerable machines. If those infected machines were connected then to a corporate network, that network will likely have been infected.
===> It's absolutely vital that you do not visit this site in any way, shape or form as it may still contain active malware that could lead to infection. <===