About Viruses

What is a virus?

Simply put, a virus is a type of software that "infects" a computer. It's typically inserted into a program, and when that program is executed, the virus activates and attaches itself to other programs in your PC. Viruses can be a simple prank--an annoying pop-up message or blue screen, for instance--but too often a virus is a malicious attempt to outright destroy data and programs.

There are several different types of viruses, but they all have a common thread that you should remember: Viruses aren't actually attached to data; they must be run in some form to infect a PC or its data. For instance, boot viruses are stored on floppies and infect a PC when the floppy is left in the drive during boot. Upon startup, the virus launches and then spreads to other floppies and wipes out data. Macro viruses are hidden within documents or data, and unleashed when the macro is run. Viruses also commonly come in the form of Web downloads and e-mail attachments, embedded in EXE, VBScript or database files.

But no matter what form it's disguised in, the virus must be triggered in order to run. So if you receive an e-mail attachment with a virus, for instance, as long as you don't open (run) the message, you should be safe. Delete the message immediately if you suspect a virus.

Viruses can infect and destroy immediately, or launch on a specified date. They can affect single desktops, or spread to entire networks, servers and Web sites. While many viruses are simply pranks or annoyances, others are more complex and their effects can be devastating. Viruses can obliterate data, corrupt programs so that they no longer run, stall servers with e-mail bombs, and--in the case of the "I Love You" worm virus--replace files, steal passwords and infect address books as it propagates itself.

How are viruses spread?

In the past, the most common way to spread a virus was through a floppy disk. But today, hackers and virus villains have a much more powerful and easier means of infecting PCs: the Internet. Web downloads and e-mail attachments are the most common ways of contracting a PC virus. And when you consider how much you--and your data--depend on both of those technologies, you realize the crucial importance of smart and safe computing. We strongly recommend that you run our virus checker, and run the full PC Pitstop tests to make sure you've applied the appropriate e-mail security settings in Outlook or Outlook Express. To help guard against e-mail viruses, you can also check out Jason Levine's Script Sentry interceptor, which checks for malicious scripts hidden in various types of files.

Also see: PC Pitstop's 5-Step Guide to Protecting Your PC.