After a long day of class, trudging from building to building and struggling to stay awake, you stumble into your room. During a quick e-mail check, just before you expire for a late-afternoon nap, you see a message from your high school best friend. The text means nothing, but there is an attachment, and you can not resist the temptation to open it. Nothing is there. Disappointed, you go to sleep with a sour mood, and a hard drive newly infested with a virus unloaded from a bogus attachment.
This is a common scene at our Internet- dependent university, yet few know how to avoid computer viruses, and even fewer know how they work. With a basic understanding of the viruses, the Web we hold so dear will be a safer place for everyone.
The computer virus began to proliferate with the popularization of the Internet. A few deviants realized that by adding a small piece of code to popular programs like games or word processors, they could make people run viruses on their computer. If a person downloaded an 'infected' game and ran it, the inserted coding would also run. This coding would act as an independent program, usually made to find other programs and 'infect' them as well by inserting the same code. This in itself was harmless, but most viruses have a more sinister purpose.
'The people that develop viruses usually have malicious intent,' said Brian Rust, communications manager for the UW-Madison Division of Information and Technology. 'When triggered, a virus will disrupt, disable, cause your programs to not run well or erase files.'
The trigger for a virus could be a date, a number of replications or even another program. Fortunately, the viruses hidden in downloaded programs have largely been identified and combated by anti-virus software. But the deviants are still at work.
The most recent threat to computer health is the e-mail virus. These are spread as attachments with e-mail. They don't have to be part of a program, but can be independent. If a virus attachment is opened, it will be activated on the computer and continue to infect other computers via e-mail. Many of these are easy to spot, because they have strange names, or are not identified by Windows. Some, however, are exceedingly creative in their intent to destroy.
The Melissa virus of 1999 was an e-mail virus, disguised as a Microsoft Word document. When opened, it automatically sent e-mails to the first 50 people on the address list of a computer, each containing the virus attachment. It spread at an exponential rate and caused large companies to shut down their e-mail servers. But, as with all other e-mail viruses, the attachment could have been erased rather than opened, thus stopping the virus.
The same is true for virtually all computer viruses. If the program they are attached to is not opened or run, they cannot affect the computer. Most anti-virus software is based on this premise, so it finds the virus before it is run and delete it. With e-mail viruses, caution is the best medicine.
'Avoid opening attachments that have an odd subject, or if there is an attachment that is not mentioned in the message, don't open it,' Rust said. 'We try to get the word out on a virus as quickly as we can, but it pays to be cautious.'
