One recent afternoon, the antivirus system on our corporate server intercepted an inbound, virus-infected e-mail. As is always the case whenever this happens, an automatic reply was sent to notify the sender that they are infected. This particular sender, completely misunderstanding the message, called to tell us that we had sent him a virus, when in fact, we had only sent him notice indicating that he had sent us one.
Anyway, the truly interesting aspect of this whole story is that the infected e-mail sender was a complete stranger! So, how did he even obtain our company’s e-mail address? The answer, more than likely, involved a chain e-mail. You’ve seen one of those,
“Forward this e-mail to as many of your friends as you can so that they can all click on a link on a website that’s donating a nickel to <
The Chain Gang
Knowing this, it’s easy to see how a total stranger can come to possess your e-mail address. You receive a chain e-mail from a friend. That e-mail was probably addressed to at least a dozen other people you may or may not know. Of course, you know better than to forward these things, but somebody else is sure to do exactly as the message says. Depending on how they forward it, and depending on what type of e-mail client they use, your name may wind up in their address book. If they forward it without snipping the thousands of previous recipient addresses (as is typically the case), then your address gets to ride along to the next wave of recipients. This can continue until your e-mail address is scattered far and wide.
Enter the virus: Imagine now that a virus infects somebody’s PC. They have your e-mail address in their address book because a friend of a friend of a… Well, you’re probably starting to see how a complete stranger can wind up with your e-mail address. Viruses will comb through address lists on infected computers, sending copies of themselves to everyone that person knows. Very often, the victim of this infection will not even know that this is happening as it tends to happen as a background process. The first sign of infection is often a reply from somebody’s antivirus software – just like in the story that I related.
Of course, the moral of the story here is, “Don’t forward chain e-mail.” They are almost always hoaxes, urban myths, outdated or just plain incorrect. And now, you can see why the passing of chain e-mail is so dangerous!
What Is A Virus (Or Worm Or Trojan)? So how else should you protect your PC from viruses? Let’s start by examining what a virus really is and what you can do to protect your computer.
The word “virus” is typically used in a generic fashion to describe anything that infects a computer, whether spread via e-mail or downloaded from a website. For the purists however, a true virus falls into the “self-replicating” category and is a piece of code that infects or attaches itself to another file (such as a Windows operating system file).
Similar to viruses are worms. Worms are also self-replicating, but are able to stand by themselves while replicating and don’t need to attach to another file. Worms often have their own built-in e-mail capabilities and can send copies of themselves without using your e-mail client.
Next are the Trojan horses, which can’t replicate themselves, but must be downloaded or e-mailed by someone. Trojans are programs that masquerade as harmless applications or games or utilities while wreaking havoc on your system. Keep this in mind the next time someone e-mails you something that claims to be able to improve your computer’s performance or is supposed to “do something really cool” when you double-click it!
How You Can Protect Your Computer
Let me start by saying that the real focus should be on how to protect your data because in protecting your data, you’ll also be protecting your computer. After all, a virus can toast your operating system, yet only an hour or two spent loading the manufacturer’s recovery CDs will have you up and running again. But what about all of those word processing documents and spreadsheets and financial records? What about your digital photos and MP3s? These are what you stand to lose if your computer becomes infected.
To protect these files, you should be making frequent backups onto removable media such as CD-RW or Zip disks. Most newer computers now come with CD-RW drives or Zip drives that are capable of storing backups of your most-prized files. Floppy drives will work for some people with few and small files, but their storage limitations will likely render them useless in the near future. Software is available to make backing up files less painful, but is not necessary if you keep your files neatly organized.
Antivirus Software Is Essential
Maintaining backups however, is only part of the strategy. Running a good antivirus program is absolutely essential these days. If you have Internet access and you swap e-mail with anybody, you will encounter a virus. In my experience, this is not just a grave danger; it is not just highly likely – it is inevitable. Good antivirus software will not only scan all of your e-mails for viruses, it will also log onto the manufacturer’s website at regular intervals to download antivirus updates. It will perform occasional system scans to ensure that nothing has slipped past its watch between updates. There are many such antivirus programs available, but make sure that you understand their basic operation and can verify that they are working. I’ve found that if I ask somebody whether or not their antivirus software is up-to-date and working and receive, “I’m not sure” as the answer, it typically isn’t and hasn’t been for some time. You should feel comfortable enough with your antivirus software to know how to check up on it from time to time.
“What about those free online scans?” you may be asking. I would avoid those for two reasons: First of all, they’re not capable of watching your computer at all times. Secondly, there’s no such thing as a free lunch – even on the Internet. You run the risk of loading “spyware” onto your computer when you open it up for such scans. (Spyware is another topic entirely, but can be described simply as software that is installed onto your computer – often without your consent or knowledge – for the purpose of watching your activities. Silent reports are sent to some entity who is interested in what music you enjoy; where you go on the web; etc.).
Good antivirus software will allow you to enjoy the Internet without risking viral catastrophe, not to mention the embarrassment of having to explain to all of your friends, acquaintances and business contacts that you are “one of those people without antivirus software,” right after sending them a dozen copies of some virus that’s been cruising the Internet for a couple of years.
Things To Keep In Mind
Most antivirus software will give you a year’s worth of free updates. Beyond that, you’ll have to pay for annual renewals. The cost for these renewals is modest – typically less than $20. Renewals are easy to do and you really can’t opt out; otherwise, your protection will be compromised.
Treat e-mail attachments with caution, especially if they’re from somebody you don’t know. If you do know the sender, save the attachment to a safe place on your computer and run a manual antivirus scan against it. If you don’t know the sender, you should probably just delete the e-mail, attachment and all. Additionally, and this isn’t a hard-and-fast rule, many virus-laden e-mails have very poor grammar and/or misspellings in the body of the message or in the subject line. Watch for those!
Attachment file extensions are often indicative of an infectious payload. If the attachment comes with a file extension such as .EXE, .BAT, .COM or .PIF, beware! These are executable files. Although executable files are not inherently harmful, you should be cautious when dealing with them in e-mail. Even more dangerous are .VBS files – just delete them!
If somebody gives you a floppy disk, CD or Zip disk, make sure to run a manual antivirus scan on it before opening any of its contents. The same goes for any files that somebody may send you through any of the various online file transfer services or chat engines (e.g. ICQ; IRC; AOL Instant Messenger; etc.).
New viruses are discovered almost daily. There is always a small risk of infection before a new antivirus update becomes available. Although this period is brief, it’s still possible to become infected by a very new and very fast-moving virus (e.g. the “I Love You” virus). The larger antivirus software manufacturers’ websites will often have downloadable tools for removing such infections, if necessary.
Virus infection can be prevented through simple measures. Armed with basic knowledge of what viruses are and how they operate, you can easily avoid dangerous practices (like sending chain e-mail and opening attachments from strangers). Through proper use and maintenance of a good antivirus program, your risk of infection is even lower. If you find yourself infected, don’t panic! Your antivirus software manufacturer is probably on the case already and will quickly provide you with an antivirus update and removal tool.
Knowing how to protect yourself from viruses is key to safely using the Internet and e-mail. If all else fails, you’ll have those current Zip or CD-RW backups of your valuable files to save the day – right?