Table of Contents
What is a Virus? .............................................1 HOW A VIRUS INFECTS YOUR SYSTEM: .............................2 HOW DOES A VIRUS SPREAD? .....................................3 BIGGEST MYTH: "I BUY ALL OF MY PROGRAMS ON CD ROM FROM THE
STORE". STORE BOUGHT SOFTWARE NEVER CONTAINS VIRUSES.... 3 INFECTION (DAMAGES) ..........................................4 PROTECT YOUR COMPUTER, NOW!! ................................ 5
A virus is an independent program that reproduces itself. It can attach itself to other programs and make copies of itself (i.e., companion viruses). It can damage or corrupt data, or lower the performance of your system by using resources like memory or disk space. A virus can be annoying or it can cost you lots of cold hard cash. A virus is just another name for a class of programs. They do anything that another program can. The only distinguishing characteristic is the program has ability to reproduce and infect other programs. Is a computer virus similar to a human virus? Below is a chart that will show the similarities.
Comparing Biological Viruses & Human Viruses
Human Virus Effects
Attack specific body cells' Modify the genetic information of a cell other than previous one. It performs tasks. New viruses grow in the infected cell itself. An infected program may not exhibit symptoms for a while. Not all cells with which the virus contact are infected. Viruses can mutate and thus cannot clearly be diagnosed. Infected cells aren't infected more than once by the same cell.
Computer Virus Effects
Attack specific programs (*.com,*.exe) Manipulate the program: The infected program produces virus programs. The infected program can work without error for a long time. Program can be made immune against certain viruses. Virus program can modify themselves & possibly escape detection this way. Programs are infected only once by most viruses.
There are many ways a virus can infect you system. One way is, if the virus is a file infecting virus, when you run a file infected with that virus. This particular kind of virus can only infect if YOU run the program! This virus targets COM and EXE files, but have also been found in other executable files. some viruses are memory resident which will infect every file run after that one. Other are "direct action" injectors that immediately infect other files on your hard drive then leave. Another way viruses infect your system is if they are polymorphic. Polymorphism is where the virus changes itself with every infection so it is harder to find. Also, virus writers have come up with a virus called a multipartite virus. This virus can infect boot sectors and the master boot record as well as files therefore enables it to attack more targets, spread further and thus do more damage.
A computer virus can be spread in many different ways. The first way is by a person knowingly installing a virus onto a computer. Now the computer is infected with a virus. The second way is inserting your disk into an infected computer. The infected computer will duplicate the virus onto your disk. Now your disk is a virus carrier. Any computer that comes in contact with this disk will become infected. For example, I once caught a virus from Cochise College by copying two non-infected disks, the computer was infected. What if my friend borrows an infected disk? Your friend's computer will most likely become infected the instant that he/she uses your disk into a computer. The third way, is the Internet. A lot of programs on the Internet contain live viruses. However, there seems to be countless numbers of ways to become infected. Every time you download a program from somewhere or borrow a disk from a friend, you are taking a risk of getting infected.
Computer software bought in stores have been know to carry viruses. " How? CD-ROMS are...