Its the news around the world that the Facebook employees computers was attacked by certain people. The employees whose laptops were hacked were running the latest & updated anti-virus software as well as updated OS & softwares. But Facebook said the hacker used  a "zero day" exploit, or a malicious software that had never been used before, making it impossible for security tools to stop it. The attack occurred when employees visited an infected website belonging to a mobile developer. Read more