Malicious Mobile Code

Chapter 6. Trojans and Worms

“Hey, Roger, come here! Let me show you something!” says a friend. He proceeds to show me the funny joke program that someone has sent him via email. He clicks the attached file. It displays some whimsical graphical routine, some music, maybe a few sounds, and ends. It’s so cute. Rarely a day goes by that I don’t see someone running a joke executable sent to them by a friend. That’s what Trojan writers are counting on. If you’ve ever run a joke executable, you’ve risked a worm/Trojan invasion.

One of the most popular games ever sent by email was “Whack-a-Mole.” Like its amusement center counterpart, it challenges players to hit animated moles on the head before they disappear into their holes. The more moles you whack, the higher your score. My daughters have mastered the art of hitting the furry mammals before they have even jumped up. A large percentage of the copies floating around the Internet contain the Back Orifice Trojan horse program. While running the game, the malicious code opens up a back door on the computer and advertises its successful break in to hackers around the world. The hackers watch the user play their game, and snicker to themselves. They wait for users to type in login names and passwords, recording each diligently. If the invaded users are lucky, the hackers are only teenagers out to play pranks. But it could be a professional hacker looking for valuable data. If you are like me, you do a lot of banking and purchasing online. ...