A few years back, in the movie Independence Day , Jeff Goldblum stopped an intergalactic invasion by uploading a computer virus into the aliens ' mothership and thereby scrambling the alien system.
A computer virus is program code secretly added to, or attached to, a file or email message that makes mischief when the file or message is opened. Often, the virus is designed to reproduce and spread itself from the file it travels in ”its host file ”to other files.
Computer viruses are created by immature, sick people, who get a thrill out of cheap little tricks ”viruses that display silly messages on your screen ”or major attacks ”viruses that crash whole computer systems.
If you saw Independence Day , you might have wondered, "If Jeff Goldblum puts a virus on the Internet, and I happen to download a file containing that virus, what might happen to my computer? Would I still be able to conquer Earth? Can I get Jeff to come over and fix it?"
Viruses are a significant threat to anyone who spends time online, uses email, and downloads files. It's just plain silly to work on the Internet and not arm yourself with some protection.
To play it, try to limit your downloading choices to commercial sites or reliable shareware sources (such as Shareware.com). Big suppliers regularly scan files for viruses. In addition to exercising caution about where you download files from, you should also install and use a virus scanning program, such as Norton AntiVirus, which can find viruses in files and, in some cases, kill the virus while saving the file. And, make sure to keep your antivirus software current by regularly downloading the updates to it from the manufacturer.
Remember : A virus in a file does no harm until you open the file (or run the program, if the file is a program). So you can download anything safely, and then scan it with the virus program before you ever open or run it. If the virus program detects a bug it cannot remove, just delete the file to delete the virus.