How Viruses Are Transmitted

• Running an executable that is infected.
• Working with a document with an infected macro
• Booting up the computer with an infected disk in the A drive

You can not get a virus from merely reading an email! You get viruses by opening the attachments associated with an email. Some mailers (older versions of Outlook Express, for example) will automatically open any attachment for you. If your mailer does this. Turn the feature off. If you can’t turn the feature off, get a new mail program.

Types of “Viruses”

Virus

A virus is a program that propagates itself by infecting other programs on the same computer. Viruses can do serious damage, such as erasing your files or your whole disk, or they may just do silly/annoying things like pop up a window that says "Ha ha you are infected!" True viruses cannot spread to a new computer without human assistance, such as if you trade files with a friend and give him an infected file (such as on a floppy or by an email attachment).

Worm

Like a virus, a worm is also a program that propagates itself. Unlike a virus, however, a worm can spread itself automatically over the network from one computer to the next. Worms are not clever or evil, they just take advantage of automatic file sending and receiving features found on many computers.

Trojan horse

This is a very general term, referring to programs that appear desirable, but actually contain something harmful. The harmful contents could be something simple, for example you may download what looks like a free game, but when you run it, it erases every file in that directory. The trojan's contents could also be a virus or worm, which then spread the damage.