Tech 101: How a denial-of-service attack works

(AP) -- Investigators are piecing together details about one of the most aggressive computer attacks in recent memory - a powerful "denial-of-service" assault that overwhelmed computers at U.S. and South Korean government ...

Spam down but 'zombie' armies growing: McAfee

Hackers appear to be beefing up armies of "zombie" computers to recover from a major hit scored in the battle against spam email, according to software security firm McAfee.