Virus Facts and Fictions
   
 

   
The Internet is constantly being flooded with information about computer viruses. Email messages often request users to pass warnings along to all their friends not to open messages with certain subject lines or authors, or describe frightening stories about "friends" who ruined their hard drives when they contracted a virus through a downloaded file.

Anyone with an email account has been traumatized by at least one of these, but most are hoaxes. Let’s explore the realities of viruses and the Internet.

First of all, you don't need to worry about spreading a computer virus to your PC just from reading your email. That's because simply reading an ASCII (text-only) message cannot spread a virus to your computer. In order to spread, the virus itself must be executed, and reading an email message does not do that.

This means, however, that files attached to an email message, which can contain executable files, could be infected. While there's ordinarily a small risk of this, all such files should be scanned before being used or opened. You need to be especially careful if there's a Microsoft Word document attached. Many MS-Word files employ the use of Macros, which can contain viruses. This applies to Microsoft Word, version 6.0 and higher.

If your email program is configured to run (open) MS-Word automatically to read attached documents, you could infect MS-Word with a macro virus. The risk is smaller, but also applies to MS-Excel spreadsheets. If you have such a feature enabled, disable it, so that you can check the file first.

Finally, if there's any doubt (especially if the file was sent by a stranger), deleting unsolicited files would be the safest thing to do. Remember the old saying, "curiosity killed the cat"? Don't expose your data to unnecessary risk from opening a file an unknown person has sent you.

The only "real" email viruses, then, are the warning messages themselves, which are forwarded over and over to hundreds of thousands of people, thereby clogging the Internet, but what about contracting viruses through the Internet in other ways?

Merely being connected over a telephone line can NOT transfer viruses, so you can't infect your computer simply by being on the Internet. However, it is worth mentioning the potential risks involved in viewing some Web pages, and in downloading some files.

Let’s first put the whole virus issue into perspective. There are only about 500, not "thousands," of different viruses. Claims of much larger numbers tend to come from anti-virus companies and are simply passed without substantiation from one person to another.

Anti-virus firms tend to count even the most insignificant variations of viruses for advertising purposes. When the Marijuana virus first appeared, for example, it contained the word "legalize," but a miscreant later modified it to read "legalize." Any program which detects the original virus can detect the version with one letter changed -- but anti-virus companies often count them as "two" viruses. These obscure differences quickly add up, and fuel consumer fears (which improves anti-virus sales, of course). The clear majority of "new" computer viruses discovered these days are only variations of well-known viruses.

Another popular myth is that bulletin board systems and shareware programs spread most viruses. "The truth," said then-PC Magazine publisher Bill Machrone, "is that all major viruses [up to late-1988] were transmitted by [retail] packages and private mail systems, often in universities." What Machrone said back then applies even today. Indeed, a late-1996 column of his says "I've been downloading files for more than 15 years, and not only have I never gotten an infected file from shareware, I don't know anyone who has, either."

The real danger comes from the software you buy off the shelf. Hundreds of retail companies have admitted accidentally spreading infected master disks to hundreds of thousands of customers since 1988 -- compared to only dozens of shareware authors who spread viruses on master disks to a few thousand customers since 1990.

Many retailers also routinely re-shrink-wrap returned software and put it on the shelf again. Do you know for sure you alone touched those master disks?

Bulletin boards, shareware authors and on-line software retailers work extraordinarily hard at policing themselves to keep viruses out. System operators for these organizations regularly check every file, and are in touch with reputable international networks which help spread the word about dangerous files. After all, these viruses would destroy their systems before they reached yours.

Viewing web pages that use ActiveX objects is NOT regarded as being safe from viruses. This is because ActiveX objects are executable files, first downloaded by Microsoft's Internet Explorer, then run by your PC, and thus CAN be used to spread viruses. To be on the safe side, consider using the security option in your browser to disable ActiveX support.

On the other hand, viewing web pages that use Java applets IS regarded as being safe from viruses. Although the web browser does download Java applets, they are run in a restricted environment, and are not given access to the PC's hard disk, thus providing a high level of safety.

As for files that you download, a virus can't spread to a PC during the downloading process. However, since a downloaded file could be infected, be sure to scan for viruses before installing and using them.

Finally, this author recommends the following:

  • By all means, DO invest in an anti-virus program; buy it yourself and register with the company. This is not the time to "share" the purchase of software with a friend. A registered version will allow you to download upgrades, so if a new virus DOES appear, your software will read it. You may not need protection from the Internet, but you should shield yourself from the disk your child brings home from a school friend, or the disk you buy off the shelf.
  • Don’t use a web browser or email program to run programs.
  • If you receive information about a virus which you feel is legitimate, don’t spread hysteria by passing is along to your friends. Instead, pass it along to your Internet service provider or to the computer security manager at your company to validate it first.
  • Keep a backup of your files; that's always a good thing to do.

 

Reliable Web Sites Related to Internet Viruses

 

The above information was compiled by CantonSouthDakota.com, and appeared in part, as an article in @Internet magazine.