In the traditional scenario, it was an individual, highly technical and working alone, who would write a virus program and then introduce it onto a computer, network server, or the Internet. Why? Ego, revenge, sabotage, and basic disgruntlement have all been cited as motivations.

Now, however, it takes no special skill to create a macro virus, a mass mailer, or other virus with highly disruptive potential. In fact, "virus kits" proliferate on the Internet and are free for the taking for anyone who wants to try their hand at disrupting the Internet or corporate communications.

And increasingly, organized crime from remote countries are getting into the act by creating sophisticated spyware programs and phish sites. Distributed by a million spam messages, these exploits are low-effort but are rewarded with a high potential for yielding personal information such as passwords, social security numbers, credit card numbers, and so on.

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