Hackers broke into the U.S. online recruitment site's password-protected resume library using credentials that Monster Worldwide Inc (MNST) said were stolen from its clients in one of the biggest Internet security breaches in recent memory.

On August 21, Symantec published a report on its Web site that said it had found copies of scam e-mails that the engineers of the attack were using, with the aim of getting information that was more valuable than just the names and contact details of Monster.com users.

Pretending to be sent through Monster.com from job recruiters, the e-mails asked recipients to provide personal financial data, including bank account numbers. They also asked users to click on links that could infect their PCs with malicious software.