Is your PC plagued? - includes related articles on antivirus software and identifying viruses - Technology Information

Home Office Computing, Oct, 1996 by Carol S. Holzberg

When Megan Corbett turned on her computer one morning last spring, she received an ominous message: A virus had attacked a critical system file. Corbett, who contracts Russian language interpreters and translators from her three-person office, pictured her precious data going down the drain. "Everything we have for this company is on this computer," she says. "Client statistics, job types information, database, accounting, payroll information--everything."

How had the pest infected her system? "We have access to the Internet, so it's possible [that I downloaded the virus]," she speculates. But more important than finding out the invader's origin was saving the data--and preventing the virus from spreading throughout the office.

Fortunately for Corbett, all that was lost was half a day's work, spent on the phone with technical support representatives at an antivirus software publisher. They eventually solved the problem and gave the computer a clean bill of health. But the consequences could have been disastrous.

Like Corbett, the last thing you need when rushing to meet a deadline is a machine that won't boot, a keyboard that types its own agenda, or a monitor with a flaky disposition. At best, hardware troubles result in downtime. At worst, they put important business data at risk. When glitches persist even after you machine returns from the shop, or applications crash no matter how many times you reinstall them, it's time to look elsewhere for a solution. Operating snafus may be symptomatic of a computer virus rather than a hardware problem. Here's how to recognize a computer virus and the steps to take to protect yourself.

BORN TO BE WILD

Computer viruses are villainous bits of programming code that find their way into a system through contaminated files brought in on floppy disks or downloaded via modem from the Internet. If you don't remove them, these intrusive, often destructive digital nasties could bring your business to an abrupt stop by rendering your computer inoperable or by destroying important--sometimes irreplaceable--office records. More than 8,000 computer viruses have been identified to date. Each month, 150 to 200 new ones appear. The overwhelming majority of these electronic creepy crawlies affect DOS/Windows-based computers. Yet even Macs are not immune.

Although viruses vary with respect to payload, they all share some basic features. Each one tends to be a rather small, stand-alone application that spreads by replication without user permission. Attaching to executables (files with the extension BAT, EXE, or COM), certain kinds of data files (such as Microsoft Word, WordPerfect, and Lotus Word Pro documents), or a disk's boot sector, the virus copies itself whenever you open an infected file, run an infected application, or boot from an infected system. Rogue programming code that carries out its dirty work but doesn't replicate when it invades a computer system is more appropriately called a trojan.

Last year a new type of virus that attacks data files (rather than executable files) appeared. Identified as the Word Macro virus, this script-based intruder initially seemed to infect only Word for Windows files. Written in WordBasic macro language, however, it easily transferred viral code from PC to Macintosh (and vice versa) since Windows and Macintosh Word applications share many file formats. Macro viruses get their name by hiding in macros, those tiny applets, programmed and perform a series of tedious or repetitive tasks.

Whatever the type of virus, it's sure to wreak havoc at the office by disrupting normal computing activity. Viruses have been known to hide all hard-disk files, format a hard disk without permission, and prevent a computer from booting. Easy to control if caught at an early stage, viruses frequently cost a business time and money when left to run their course.

AVOID AN OUTBREAK

The good news is that viral infection is not inevitable. A healthy does of paranoia, coupled with some preventive maintenance, will keep your system in tip-top shape. Don't turn on your computer without having taken the following six steps.

1. Keep a clean (uninfected), bootable start-up disk on hand. In the event a virus invades your system and renders your hard disk unusable, a bootable floppy will let you access your hard drive and initiate repair procedures.

If you work on a computer with Windows 3.1, you can create a bootable system disk by typing "format /S" at the DOS prompt. Be sure the start-up floppy has a copy of your AUTOEXEC.BAT and CONFIG.SYS file in addition to a file called COMMAND.COM.

If you work with Windows 95 and you didn't create an emergency start-up disk when you installed the operating system, you can make a bootable system disk by clicking the Start button on the Taskbar, choosing Settings (from the Start menu), selecting Control Panels, double-clicking on the Add/Remove Programs icon, selecting the Startup Disk tab, and then clicking the Create Disk button.

If you use a Mac, prepare a start-up disk containing a stripped-down version of the System folder. Include a copy of the Finder, appropriate System Enabler, and basic Extensions. You can create a Mac start-up disk with Apple's 7.5 Installer. Alternatively, you can use the Disk tools floppy that comes with System 7.5 or boot from the System CD-ROM if your machine is equipped with a CD-ROM drive and supports that feature.