The dotCrime Manifesto

Chapter 9. Stopping Botnets

In computer security, a Trojan is a program that contains hidden malicious code. Tools circulating on the Net allow code to be added to any program file to turn it into a Trojan. When the modified program is run, the extra code runs in the background.

Before the Internet, the worst a Trojan (aka virus) could do was to “trash” the infected machine: delete a few files, write rude messages, make some noise. Machines with access to the Internet provide the attacker with much more scope for exploiting the captured machine. Installing a “backdoor” program allows the attacker to control the machine remotely. He can install any program he wants, open or close the CD drawer, or even turn on a video camera to watch the user ...