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The subject of today's blog is computer viruses, focusing on what they are and what you can do to keep your computer from being infected by them. Wikipedia defines a computer virus as "a self-replicating computer program that spreads by inserting copies of itself into other executable code or documents." The three major types of computer viruses are:
Trojan horses - Viruses that claim to do one thing, but install themselves on your computer, and probably do some damage to your computer when you open them. Have you ever received an email with an attachment that said something like, "Click here to see pictures of the sexiest cheerleaders in the world?" The attachment was probably a Trojan instead of a photo. If the attachment's file name was something like ".vbs," I guarantee you it was a virus.
Worms - It's a virus program that makes copies of itself when you download it. Worms are very common computer viruses and can be hard to detect.
E-mail viruses - They use emails to transport themselves across the vast wasteland of cyberspace. Often, when you download one it will send itself to every person in your address book. A few days ago I was busy doing something and a pop-up window that was supposed to be from Microsoft told me to click it and update a program. I carelessly let it start downloading. By the time I realized it was a virus scam, it had already started sending itself to the people in my Outlook address book.
A very brief history of computer viruses:
1949 - Theories for self-replicating computer programs developed
1981 - Viruses that infected Apple computers released through Texas A & M pirated computer games
1982 - The first computer virus to appear outside the computer lab where it was created, the
Elk Cloner, It was written by
Rich Skrenta.
1986 - First PC virus, named
(c)Brain. It was written by Basit and Amjad Farooq Alvi.
1987 - Lehigh virus
1991 - Tequila polymorphic virus
1992 - 1300 viruses are known to exist
1994 - Good Times email hoax
1995 - Word Concept virus is spread through Microsoft Word documents
1996 - Baza, Laroux, and Staog viruses are released
1999 - The Melissa virus is released by David Smith, who later went to prison. It infected one million PCs.
2000 - The Love Bug virus was released. It infected millions of computers, did millions of dollars worth of damages, and shut down websites such as Amazon, Yahoo, and eBay for hours. Another gift package from the Phillipines.
2001 - The Nimda virus, the Anna Kournikova virus, and the Sircam virus appear. The CodeRed virus infects 359,000 hosts in its first twelve hours of life.
2002 - Viruses named for celebrities such as Jennifer Lopez and Brittany Spears make their Web debut. As far as I know, no viruses were named for me, darn it!
2003 - Big year for worms. The Slammer worm infects about 75,000 computers in ten minutes. The infamous Sobig worm, which infected my computer and my sister's computer, rampages the Web.
2004 - Another big year for the creeps who design worms to infect our computers. The MyDoom and Sasser worms play starring roles in the world of the worm. You don't have to open a file attachement for your computer to be infected by the Sasser worm!
Reading this list, you can see that viruses and worms are becoming more sophistcated and harder to avoid. What can you do to prevent them? First, if you don't have an anti-virus program installed on your compter, run don't walk to your computer, and download one from the Web and install it now. It will be the best $50 purchase you ever make! Never open any email attachment that ends in a extension such as ".vb or .vbs." This is a virus, without expection. Always check the description of any attachment before you open it. If it one that is unfamiliar to you, don't open it. If the attachment ends in ".exe", trash it. That means a progam will run if you open it.
If you get an email saying something like "Urgent, download now to update your system," don't fall for it. It is probably a scam. If you get an email saying something like "Free photos of whoever the current showbusiness "hottie" is, trash it.
I hope this post helps you be smarter than me so you will never download a virus or a worm on your computer.
References:
Wikipedia article on computer viruses
InfoPlease article