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• $19 for Mac or PC virus/malware removal ($89 value)

Computer Viruses: A High-Tech Flu

This deal can help protect your computer from viruses. Learn exactly what you're warding off with Groupon's look at the most common types.

The first computer virus was created not to access confidential information, corrupt data, or spam email contacts—all common motives for creating viruses today—but simply to see if it could be done. In 1971, programmers working on internet forebear ARPANET (Advanced Research Projects Agency Network) created a bug they named Creeper in order to test whether a piece of code could replicate itself. (It could, and produced the taunt "I'm the Creeper. Catch me if you can!" on the screens of infected computers.) Self-replication is the goal of all viruses, which spread through contact with another infected being via email, flash drives, or software downloads. To learn how three of the most common types spread, read on.

Boot Virus:This type of virus targets the hard drive’s master boot record, which loads the operating system at startup. When the operating system loads into the computer’s memory, the virus loads with it. Once it’s in the memory, the virus can do whatever it was programmed to do, often overwriting the master boot record with a new set of instructions. This type of virus is most commonly spread through an infected floppy disc or flash drive.

File Infection Virus:Also known as program viruses, these attach themselves to executable files—those with extensions like .exe, .com, or .sys—and then load into the computer’s memory or other programs when the file is run. This type of virus is most commonly spread when infected files are shared over email or on a flash drive.

Macro Virus: Macro viruses can hide inside documents or spreadsheets that use macros—custom actions that can be programmed into the document or spreadsheet using a macro programming language—such as Microsoft Excel or Word. The virus is written in the same programming language and infects a computer whenever an infected file is opened. This type of virus is most commonly spread when infected documents or spreadsheets are shared over email or on a flash drive. Microsoft applications now notify the user before automatically opening files that use macros—so unless you know and trust the source of a file, you should heed their warning.