A Virus is a tiny program that attach's itself to other files on your Macintosh such as Applications, the Desktop File, and the System document, among others. The virus then attaches itself to other programs on your hardrive and any disk you insert. Any infected disks coming from your infected machine will most likely infect whoever's machine it's inserted in, thus spreading the virus.
Why Should I Care?
You should care. Although you shouldn't panic over the possibility of your Mac becoming infected, you should take steps to prevent it. Some virus's are 'benign'. They don't intentionly destroy data on your machine, but sometimes play a joke or just stay hidden. But, often these virus's contain errors or bugs causing your Macintosh to bomb and possibly result in the loss or corruption of data. Other virus's do intentionly do damage, such as wiping your disk or scrambling your data. This can result in the loss of time and money attempting to reconstruct the data you had originally.
How Can I Protect My Mac From an Attack?
There are a number of virus protection programs out there, including commercial ones such as SAM, and shareware programs such as Gatekeeper and Disinfectant. Personally, I use Gatekeeper and Disinfectant. Gatekeeper loads at startup and is configured through a control panel. It keeps and eye out for known virus's, and keeps an eye on activities that might indicate an unknown virus. It then stops the virus from doing any damage. Disinfectant is an application that scans your hard disk and floppy disks for known virus's, or unknown strains of known virus's. It will then delete the virus and attempt to repair any damage it may have caused. Both are excellent and should be used religously. They are available from most Bulliten Boards and Mac User Groups. Remember, if you find a virus, check ALL of your floppies. There is a good chance that at least some of them are infected and could reinfect your machine.
If your bringing a file over to a friends house on a disk, and worried that he/she/it might have a virus, simply lock the floppy (slide the plastic tab on the left hand of the disk facing you) and there is NO WAY in hell a virus is going to get on that disk. Your completely safe!
See the next chapter for a listing of the current Mac virus's and what they do, as well as a little bit of history.
