Sometimes scare makes us aware

April 05, 1999|By Mike Himowitz

I sent my son an e-mail a couple of days ago with directions to a family gathering in Philadelphia. When I didn't get a response, I called his college dorm room to find out whether he'd received it.

It turned out he'd been busy. He's a student computer aide, and his mailbox was so jammed with messages that he'd missed mine.

"It's this Melissa virus thing," he complained.

"Were that many people infected?" I asked.

"No, I don't know anybody who's infected," he said, "but everybody's worried about it."

That's what happens when a new virus makes it into the media. A few large companies get hit and suddenly the apocalypse is nigh. In the end, however, it turns out that most people never see the bug. Remember the Michelangelo virus? It was supposed to end computing as we know it -- back in 1992.

Still, the public angst does serve a purpose. There are thousands of viruses, Trojan horses, worms and other nasty creatures out there. Should your catch one, it can put you out of business. So, if nothing else, the Melissa scare should remind you that it's smart to protect yourself -- and it isn't that hard.

First, practice safe computing. With simple precautions, you can avoid most viruses altogether. Second, buy a virus checker and use it regularly to catch anything that slips by your first line of defense.

With the explosion of Internet use in homes and business, most of today's viruses travel as attachments to e-mail messages. This doesn't mean you have to stop reading your mail. But you do have to be careful about anything that tags along.

An attachment is a file that's tacked onto a message electronically, the same way you'd attach a report, photo or check to a cover letter through the regular mail. An e-mail attachment can be almost anything your computer produces -- a Microsoft Word document, a program, a spreadsheet, a music file or a digitized picture.

An attachment usually shows up as a "paper clip" icon when you view a list of your e-mail messages, or a large icon at the bottom of a message you've opened for reading. Your e-mail program will allow you to save an attachment to disk or "open" it immediately. Or, you can ignore an attachment altogether and delete it with the message.

Two types of attachments are handy hiding places for viruses. The first is a program file, which usually has an extension of "exe." If you double-click on the icon of a program file attached to an e-mail, it will be launched then and there. If you save the program file to disk and double-click on it later, the same thing will happen.

If that program is a virus or Trojan horse, you're dead meat. That's what happened to thousands of victims of the "happy.exe" bug, which has been mailed around the Internet disguised as program that displays on-screen fireworks.

NEVER, NEVER launch an "exe" file directly from your e-mail program. Always save it to disk and give it a thorough examination with a virus checker. If in doubt, throw it out.

The newest and most insidious vehicles for virus writers are Microsoft Word documents or Excel spreadsheets, which are transmitted as e-mail attachments millions of times a day.

Although few casual users are aware of it, Word and Excel come with a programming language that allows developers to create customized functions, known as "macros," or even write entire applications using Word or Excel as a base. Unfortunately, macros also give hackers an opportunity to write viruses that execute automatically when you open an infected Word document. While many users think twice before running a program they're not familiar with, most of us open Word documents without a second thought.

Melissa is a macro virus that affects Microsoft Word 97. When you open a Melissa-infected document, it uses Microsoft's Outlook e-mail program to send copies of itself to the first 50 people in your address book and then infects every Word document on your computer. Even if you don't have Outlook installed, you can spread the Melissa Virus by sending an infected Word document to someone else.

One way to avoid macro viruses is to have Microsoft Word 97 warn you about them. To do this, select Tools from the menu bar, then click on Options and select the General tab. At the bottom you'll see a box titled "Macro protection: If it's blank, click on it to produce a check mark. That done, Word will warn you whenever you open a document with macros and give you a chance to disable them. Unless you know exactly what these macros do, disable them immediately.

To be really safe, surf to Microsoft's Web site and download a patch for Word that extends the same protection to the document template (.dot) files that Word uses for basic formatting (www.microsoft.com/security/

bulletins/ms99-002.asp). To be even safer, don't open any Word document you've received until you've saved it to disk and examined it with an updated virus checker.

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