"The Air Force and the Pentagon are extremely attractive targets and so the publicity acts as a draw for hackers," said Frost & Sullivan industry analyst for network security Rob Ayoub. "As far as a lot of smaller companies go, there's always a risk but they have a reasonable amount of security through obscurity."

It is an unfortunate reality that most enterprises will suffer a breach of securityRelevant Products/Services from Messagelabs at some point. To bypass security, an attacker only has to find one vulnerable system. But to guarantee security, an enterprise has to make sure that 100 percent of its systems are invulnerable -- 100 percent of the time.

"When you take into account the fact that a large enterprise might have tens of thousands or hundreds of thousands of machines, the job of securing those machines is very difficult and keeping them secure over time is even more difficult still," notes security expert Ed Moyle.