It happens every day all over the globe. It may take the form of an email attachment, or a floppy disk from a trusted colleague. It can even ride piggy-back on one of the most common types of computer files in the world: a Microsoft Word document.
Whatever the source, computer viruses-small, self-replicating programs-can take control of your machine, rendering your most frantic button-clicking completely ineffective and deleting or altering all or any files on your system.
With names like "Stoned," "Michelangelo" and "Dark Avenger," viruses are born in the minds of mischievous and occassionally downright malicious programmers. Once re-leased, a well-designed virus self-replicates and can spread around the world in mere days via unsuspecting floppies and the Internet.
With the rapid spread of the Internet, viruses have been afforded a fast-track distribution stream. While viruses cannot be transmitted in the body of an email message (despite urban folklore to the contrary), they can be included in attached files, including word-processing documents and executable programs.
According to Network Associates (www.nai.com), there are some 25,000 viruses "alive in the wild" today. The vast majority have no particular ill intent, but simply interfere with the normal operation of programs. For instance, one virus embedded in a Microsoft Word "macro," or stored set of instructions (one of the most common carriers of today's viruses), makes typed characters look like they are tumbling down the page and disappearing.
Another macro virus devours memory until the machine must be rebooted. Conversely, according to antivirus software vendor Trend Micro (www.antivirus.com), a third Microsoft Word macro can actually reformat your hard drive.
While the result of such viruses generally amounts to little more damage than that caused by silly pranks, some DOS-based viruses can do some real damage.
The infamous Dark Avenger virus of the early '90s secretly attached itself to any internal executable program. Every 16th time an infected program was run, the Avenger would overwrite some random part of the hard disk. In some cases, the random overwrite would cause no visible damage. Sixteen executions later, though, it might erase a key component of your operating system, disabling the computer completely.
Combine the connectivity of the Internet with the high floppy disk traffic of a university computer lab, such as those at our beloved University of Montana, and it seems like a viral recipe for disaster. With students and faculty in labs continuously transferring files over the Net and saving them on floppy drives to take home, you'd think a university town like Missoula would have been shut down by viruses by now.
But that's not the case, says Michael Peterman, UM help desk technician. "You're safe if you just use the machine", he says, adding that he's not aware of any significant viral outbreaks in the past year or so. One way Peterman helps students and faculty to protect themselves is by distributing free virus protection software at the help desk.
Viruses are not completely unheard of at UM, however. Jim Bigley, Computer and Electronic Specialist in the Department of Geology, says he's helped to exterminate 300 to 400 viruses from labs on campus in the past few years. The vast majority have been of the prankster variety-essentially harmless but annoying.
Bigley says he's aware that machines like those in labs which have Internet capability, and are operated by multiple individuals using floppy disks to transfer files are those most at risk. Of course, when those floppies are subsequently taken home and used on personal machines, a viral outbreak is born.
Bigley pulls no punches: "Users should expect to contract a virus if they use a floppy," he says. The best way to protect yourself, he says, is to run your antivirus software regularly and avoid opening files from untrusted sources.
However, because viruses can accompany files from trusted associates who have themselves been infected, there's no guarantee you can keep your data safe. Bigley tells of a faculty member several years ago who refused to believe he was the one infecting dozens of campus computers. It was finally determined that a Word document he'd received from a colleague in Japan was the culprit.
Heather Morris, support specialist at Internet Connect Services in Missoula, says that she's encountered a handful of viruses on clients' computers in her three years of diagnosing and fixing machines. "We encountered one virus which brought up an error message that the hard drive was full, even though they had about a gig free," she says.
According to the experts, there's no foolproof way to avoid viruses if your machine ever encounters files from elsewhere, via modem, network connection or disk. But it would do all of us some good to become better acquainted with viral capabilities, and install antivirus software on our personal machines.