<< Back January 2006

Hi-Tek Peru
Your technology connection in Lima
Trojans, Viruses, Worms and “things that go bump in the night”
By F. P. Nagle

During the past few months I've been writing about hardware, software and internet sites that may be of interest in helping improve your personal or business use of computers. An area that is in the news almost daily, but overlooked by many, is the “dark side” of computing. I'm referring to items mentioned in the title of this article, trojans, viruses and worms. While many of the early computer “infections” were benign or non-malignant, many of the recent files are malicious in nature, causing the infected user at the very least to have to deal with removing the infection, sometimes a very time consuming effort, to the high or destructive end, of losing everything on their computer -- and facing the 'fix' of formatting their hard drive(s) and starting over.

Before looking at your best defenses against infection I think it is important to define what the different “infections” are.

Trojans - these are ordinary looking files that carry hidden, sometimes malicious contents. Taken from www.webopedia.com -

“The term comes from the Greek story of the Trojan War, in which the Greeks give a giant wooden horse to their foes, the Trojans, ostensibly as a peace offering. But after the Trojans drag the horse inside their city walls, Greek soldiers sneak out of the horse's hollow belly and open the city gates, allowing their compatriots to pour in and capture Troy.”

This is exactly what a “Trojan” infection does to your computer. The program, or file, appears as something you may think is safe, but hidden inside is usually something harmful, most likely a “worm” or a “virus” (see below). The lure of a Trojan is you may have been sent a file thinking it is from a friend or co-worker, or you've discovered a game or picture to download thinking it's harmless. Once you execute (run) or open the file the worm or virus goes to work. Sometimes it will only do things to annoy you (slowing down the system, excessive access to the hard drive, etc. but usually a worm or virus will cause damage to your system.

Viruses - are computer programs with the main purpose of destroying data on your computer. The virus may only destroy unimportant files, or it may decide to erase all of your document files. A virus can cause an infected computer to do funny things on certain dates, as well as issue serious commands such as erasing your Registry file, thus disabling the operation and start up of your computer.

Viruses are spread through the files you obtain from friends, download off the internet, or install through a floppy disk (do you still have a floppy disk for your computer?). A virus will often come disguised under the cloak of a Trojan, which is the carrier for the virus.

Worms - operate differently. If you happen to be a Star-Trek fan, you may remember the episode with “Tribbles.” These little creatures continually replicated themselves. Worms behave the same way.

They generally come through your email, but you can also get infected if you accept a Trojan File which has a worm as its payload. If you receive a worm through your email, and execute it, the worm sends a copy of itself to all the contacts in your address book. If you happen to have a large contact/address list as I do, that means hundreds if not thousands of people will wind up receiving the worm, and so the multiplication continues.

A well known “Trojan” that was “felt” world wide was the “Love bug.” It was a perfect example of all three of the above. It was a Trojan because it came disguised as a 'Love Letter' when in reality it was carrying a harmful program. It was a virus because when you executed (or ran the file) it infected the files on your computer, turning them into new Trojans and it was a worm because it propagated itself by sending a copy out to everyone listed in your email address book.

So now that you know what's lurking out there, what do you need to do to practice “safe” computing?

• As hard as it may be, never accept files from anyone you don't know, it's easier and safer to use the “delete” key if you have any doubt about a message or file you've received.

• If you happen to see a “great” program or file while surfing the Internet, be sure that it is from a reputable or well known site.

• Don't run, or even peek at unsolicited files from people you don't know. A more prudent approach is to write (email) back to the person and ask for verification that they sent you a file. Some current viruses will send an email and the file to everyone in your contact list and then delete itself from your computer so you have no idea it has even happened.

• Install and USE a Virus Detection program. A good, and free for non-commercial use, anti virus program is available from www.grisoft.com - AVG anti-virus. I've been using this program for some time now, and it has discovered a few “infections” that I've received in e-mail as well as files I've downloaded, believing them to be utilities I could use to improve my computer's performance. Additionally, I have this program set to check daily with the manufacturer's site for updates to the list of viruses in its database.

• One last, but important step is to backup your important files regularly. With the cost of disks or USB flash drives continually dropping in price, it isn't difficult to store your important data and have it with you wherever you may go.

• If you follow all the above you have a better chance of not getting infected, but if you should, don't panic, all may not be lost. There are many programs that will “clean up” an infection, and even repair some of the files you may have thought “lost”. There are many on-line forums that can help you troubleshoot problems with “experts” willing to give you step by step instructions on getting your computer up and running again. I'll address some of these resources in an upcoming article. Until then - remember to practice “safe” computing.

<< Back