Technewsworld has a nasty Halloween Security Horror story (scroll down a bit to see the story):
Beginning about three years ago, and for two-and-half years, a bot master worked on penetrating a very large company. Always keeping well below the threshold for the in-place security systems, this guy compromised almost every computer in the company.
I won’t spoil the outcome for you, you’ll have to read the story yourself! It’s truly a nightmare scenario for both employers and employees.



