Computer Viruses, Worms, and Trojan Horses
What You Should Know

Viruses are malicious little programs that infect or invade your computer and cause a variety of problems. These evil programs are called viruses because they behave in computers and on the internet much the same way actual viruses behave in individuals and populations. Computer viruses have the ability to copy themselves and spread to other computers through infected files and documents, email, websites, floppy disks, CDs, and other media.

Once inside your computer, viruses can cause a wide variety of problems including deleting your files, erasing your hard drive, and spreading to other computers automatically through your email program or your internet connection. Aside from the damage it can cause, it is always embarrassing to be identified as the spreader of a virus.

Worms are a type virus that does not actually delete any files or cause similar damage to your computer. Worms simply replicate themselves and then spread to other computers through your email program or your internet connection. The most noticeable effect of a worm is your computer running slowly or not responding at all because the worm is using all your computer’s resources, leaving nothing for the programs you want to run.

Trojan Horses [think Greek mythology here] are malicious viruses that infect your computer disguised as innocuous or even helpful programs that, once they are run, immediately begin causing damage, replicating, and spreading to other computers.