How can we protect ourselves against viruses?

Is It Really A Virus?
First, you may think you have a virus, but how do you really tell? Viruses often cause erratic behavior, smiley faces may pop up, your screen may disappear, or your computer may crash. The trigger that activates the virus can be almost anything. For instance, the virus can be activated the minute it is installed. Or it may start its dirty work the next time you start your computer. In many cases, a virus can reside inside your computer in an inactive state, waiting for a certain event (like a certain date) to happen.
From the moment the virus infiltrated your computer to the time that it made itself known to you, you could have innocently spread the virus to others. A very disconcerting sign that you have a virus is when friends call or e-mail to let you know you have sent them a virus-infested e-mail.

A Scan Is Necessary
So you suspect you have a virus. How do you find out for sure? You scan your system for viruses with a software program. If you already own an anti-virus program and your computer is operable, you can start your anti-virus program and initiate a scan of your entire computer. However, chances are if you contracted a virus, the virus definitions that your program is using are out-of-date.

Use Your Anti-Virus Manufacturer's Web Site
If the virus scan finds an infection, it will give you the name of the virus or viruses that you have contracted. If your computer is contaminated, you need to take immediate action. Depending on the severity of the virus, the health of your computer as well as the security of your computer data may be at risk. Look up the virus at one of the anti-virus manufacturer's Web sites. Symantec, McAfee, and, Panda Software are all informative sites. Viruses vary in severity. Some are easy to eliminate and repair. Others can be very nasty, and repairing their damage could involve some complex reprogramming. If your good computer luck has returned, you may be able to remove the virus yourself. If, however, you have contracted an invasive virus, don't hesitate to leave the work to a local computer professional.

Computer viruses are everywhere. With the use of the Internet and more communications between computers, viruses are spreading faster than ever. The only way to prevent their spread is through public awareness of safe computing.

Treat any file attachments that might contain executable code as carefully as you would any other new files: save the attachment to disk and then check it with an up-to-date virus scanner before opening the file.

If your E-mail or news software has the ability to automatically execute JavaScript, Word macros, or other executable code contained in or attached to a message, I strongly recommend that you disable this feature.

My personal feeling is that if an executable file shows up unexpectedly attached to an E-mail, you should delete it unless you can positively verify what it is, who it came from, and why it was sent to you.

The recent outbreak of the Melissa virus was a vivid demonstration of the need to be extremely careful when you receive E-mail with attached files or documents. Just because an E-mail appears to come from someone you trust, this does NOT mean the file is safe or that the supposed sender had anything to do with it.

Some general tips on avoiding virus infections are:

1. Install anti-virus software from a well-known, reputable company, UPDATE it regularly, and USE it regularly. New viruses come out every single day; an a-v program that hasn't been updated for several months will not provide much protection against current viruses.

2. In addition to scanning for viruses on a regular basis, install an 'on access' scanner (included in most good a-v software packages) and configure it to start automatically each time you boot your system. This will protect your system by checking for viruses each time your computer accesses an executable file.

3. Virus scan any new programs or other files that may contain executable code before you run or open them, no matter where they come from. There have been cases of commercially distributed floppy disks and CD-ROMs spreading virus infections.

4. Anti-virus programs aren't very good at detecting Trojan horse programs, so be extremely careful about opening binary files and Word/Excel documents from unknown or 'dubious' sources. This includes posts in binary newsgroups, downloads from web/ftp sites that aren't well-known or don't have a good reputation, and executable files unexpectedly received as attachments to E-mail or during an on-line chat session.

5. If your E-mail or news software has the ability to automatically execute JavaScript, Word macros, or other executable code contained in or attached to a message, I strongly recommend that you disable this feature.

6. Be _extremely_ careful about accepting programs or other files during on-line chat sessions: this seems to be one of the more common means that people wind up with virus or Trojan horse problems. And if any other family members (especially younger ones) use the computer, make sure they know not to accept any files while using chat.

7. Do regular backups. Some viruses and Trojan horse programs will erase or corrupt files on your hard drive, and a recent backup may be the only way to recover your data. Ideally, you should back up your entire system on a regular basis. If this isn't practical, at least backup files that you can't afford to lose or that would be difficult to replace: documents, bookmark files, address books, important E-mail, etc.

We also recommend:

o SCAN for viruses all the CDs that you run programs or open documents from, even if the source of those CDs is 'secure'. There are many cases of CDs containing viruses without the intention of the producer (CDs from magazines, presentations of famous software producers, etc.).

o DON'T open e-mail attachments, even if they are presented as text files or they came from known persons. Let's take for example VBS/Loveletter: when run on a system, it sends a file (presented by the mail client as a text file) to all contacts from the address book.

o DON'T launch programs obtained from insecure sources. When you receive a text file or an executable through a discussion list, for example, don't launch it until you verify it with an up to date AntiVirus.

o Even your best friends can try to play tricks on you (innocent ones at the beginning). There are several backdoor programs distributed on the Internet and very well documented. When a friend sends you an executable file, we recommend you to scan it for viruses. The most dangerous thing is that even the backdoors can act like droppers and can spread viruses. In the second half of the year 2000, due to the large number of backdoor programs (Netbus is the best example), some worms capable of finding computers for infection using these programs appeared.

o DON'T use backdoor programs as tools for remote administration. There are many commercial or free programs that do the same thing in a safer way than backdoor programs.

o UPDATE your operating system. The new versions of Windows 2000 and Windows 98/ME give the possibility of updating through Internet. Using these updates, you will have a safer system - many viruses are based on errors in the operating system project.