Security Center: Viruses

What a virus is
How viruses spread
What viruses can do
What BCPL.NET does to stop viruses
How to avoid getting viruses
What to do if you are infected with a virus
Further Information

A virus is a program or piece of code that is loaded onto your computer, usually without your knowledge. Viruses are not created naturally - it actually takes a human being to write a virus. Once a system is "infected", viruses can do many things - but this all depends on what the virus was intended to do in the first place.

In the old days, before e-mail, viruses were generally spread via the sharing of infected floppy disks. Now that e-mail is more common, people have discovered ways to write viruses that are able to read the address books in your computer, and then send e-mails to everyone listed (called mass mailers). These e-mails would then contain attachments, with copies of the virus itself in the attachment.

Some viruses merely spread around without any noticeable effect on an end user's computer. In other words, there's no "payload" - the virus doesn't really do anything to your computer. The impact this type of virus has is an increase of e-mail traffic at the server level, and a slow down at the user's level to the increased volume in inboxes. Many corporate e-mail servers have experienced a crippling amount of traffic due to virus outbreaks. Also, when viruses are being sent out by an infected computer, there is usually no way for the user to tell - the infected messages that were sent out by the infected machine do NOT show up as "sent items" in the user's e-mail program.

Other viruses may heavily impact the way that your computer operates. It may infect other files on your system, making them unusable. It may eat up your system's memory, causing your system to dramatically slow down or even crash. It may even delete or rename files of certain types on your hard drive.

One of the worst types of viruses sends out personal documents from your computer to random entries in your address book. Clearly, this behavior could be disastrous, especially in a business setting. The Klez Worm exhibits this behavior. Other similar types of viruses may record things that you type on the keyboard (called key-loggers), including passwords, credit card numbers, and bank account information (ie. anything you type on your computer).

Another type of virus is called a trojan horse or trojan - that is, a virus which takes over your system and allows others to control it from across the Internet. A firewall, which filters incoming connections to your computer, may prevent others from being able to control your computer, but it will not eliminate the virus from your system.

BCPL.NET installed a Barracuda 400 anti-spam and anti-virus firewall in January of 2005. The Barracuda sits between the Internet and our mail server, pre-processing all incoming e-mail before relaying it on to the mail server. Incoming mail identified by the Barracuda as virus e-mail is blocked before it can reach the mail server.

No current technology is 100% accurate in identifying virus and spam e-mail, so don't expect miracles. Do not relax your guard! Continue to be on the lookout for suspicious e-mail in your Inbox. Continue to use anti-virus software on your PC, and continue to keep it up to date. The Internet is full of nastiness these days. Regardless of what BCPL.NET tries to do to defend you from them, never forget that you are your own final line of defence against the bad guys.

The Barracuda should block most virus e-mail, but some will still slip through. Furthermore, the Barracuda processes only e-mail coming to BCPL.NET from outside. It can't process mail sent by BCPL.NET customers. If a customer's PC is infected, it can still send out infected e-mail.

We will gradually turn on more advanced features as we become more familiar with the Barracuda, and will use future BCPL.NET News messages to explain what those features are and how they affect your e-mail. Stay tuned for future developments.

If you're interested in learning more about the capabilities of the Barracuda 400 spam and virus firewall, visit the Barracuda Networks web site at http://www.barracudanetworks.com

For more information on the Barracuda, see our Spam and Virus Firewall FAQ.

It isn't difficult to protect your computer against viruses. The vast majority of viruses are designed to infect PCs running the Microsoft Windows operating system. Because of this, Windows users should pay very close attention to the recommendations below. Viruses aimed specifically at Macintosh OS and UNIX computers are rare, but that doesn't mean Mac and UNIX users should let their guard down.

1. Install Anti-Virus Software
   We recommend that all owners of computers connected to the Internet install anti-virus software. If you have anti-virus software on your computer, if it is configured correctly, and if you keep it up-to-date, the chance of a virus infecting your computer will be greatly reduced.
   
   In addition to protection against viruses spread via e-mail, anti-virus software installed on your computer also protects against viruses that spread via other means (for example, viruses in files downloaded from web sites and FTP sites).
   
   There are many anti-virus programs available. We cannot recommend any one in particular, but the two most popular and most easily obtained are McAfee Virus Scan (http://www.mcafee.com) and Norton AntiVirus (http://www.symantec.com). Both can be purchased directly from the vendor or from almost any computer store.
   
   
2. Keep Your Anti-Virus Software Up-to-date
   Anti-virus software is not an "install it and forget it" proposition. Most anti-virus programs use a virus description database to know how to detect and destroy specific viruses. If that database is not kept up-to-date, the anti-virus software will not know how to deal with new viruses. Most anti-virus programs have an "update" feature that will download and install the latest virus description database. You should make sure the updater runs fairly often - at least once a week, but preferably more often. If you don't, your anti-virus software will be useless because it won't know about new viruses. In fact, you should run the updater immediately after installing anti-virus software. The virus description database included on the installation CD only knows about viruses that existed when the CD was created. Depending on how long it has been sitting on the shelf before you buy it, it can be seriously out of date.
   
   You must keep your anti-virus software up to date. If you don't, you might as well not have installed it in the first place. Out of date anti-virus software is fairly useless.
   
   Please consult the documentation included with the anti-virus software for specific information regarding updates.
3. Watch out for E-mail attachments
   This is incredibly important: DO NOT OPEN UNEXPECTED E-MAIL ATTACHMENTS. This is the prime cause of people getting viruses. Many virus-infected e-mails try to trick the reader into opening the attachment by writing something in the message body to make you curious, and thus more likely to open the attachment. Don't be fooled!
   
   If you are not expecting an attachment, even if it seems to be coming from a friend, do NOT open it unless you contact the sender and verify that he/she intentionally sent you an attachment. Many people assume that if an e-mail comes from a friend, it is safe to open. This is NOT TRUE. In fact, most viruses come from your friends, because you are most likely listed in their address book (remember, viruses tend to send to every person in an e-mail program's address book).
   
   If you send a file attachment to someone else, explain in the message text what the file is and why you are sending it. Even better, send two messages. In the first, explain that your next message will contain a file attachment, and explain what it is and why you are sending it. The second message should contain the attachment, and should repeat the description in the message text. This may seem cumbersome, but an increasing number of virus-wary (and virus-weary) e-mail users simply delete all messages with file attachments.
   
   Official e-mail from BCPL.NET staff never includes file attachments and is sent ONLY from the following five addresses:
   If you receive official-looking e-mail from any other address ending with "@bcpl.net", it is NOT from us and probably contains a virus.
   
   
4. Keep Your Software Up To Date
   Even if you never intentionally open an unexpected file attachment, it is still possible under certain circumstances for an infected file attachment to infect a Windows PC.
   
   Microsoft Outlook and Outlook Express use Internet Explorer as a "helper program" to open certain types of file attachments. Several versions of Internet Explorer have a bug that makes it possible for a certain type of e-mail file attachment to open automatically even if the "auto open" option is disabled in Outlook or Outlook Express. Some viruses are designed to exploit this bug. This bug has been widely publicized and Microsoft provides a patch for the affected versions of Internet Explorer, but a lot of people are still running the buggy unpatched copies of Explorer.
   
   Because of this bug, and other bugs like it that are constantly being discovered in Internet Explorer, we recommend that all users update Internet Explorer on a regular basis (at least once a week if possible). For Windows users, go to http://windowsupdate.microsoft.com.
   
   Other (i.e. non-Microsoft) mail programs and web browsers are not known to have similar bugs, but it is possible that some day a virus programmer will discover a bug in one of them and find a way to exploit it. No matter what mail program and web browser you use, it is wise to check the vendor's web site frequently for updates.
   
   
5. Pay Attention To BCPL.NET Virus Alerts
   When we become aware of a virus that poses a serious threat, we send out a BCPL.NET News message about it. Pay attention! The health of your PC may depend on it. An archive of BCPL.NET news messages can be found at: http://www.bcpl.net/news/

For more information on viruses, and for the lastest news regarding viruses and virus hoaxes, visit one of the following websites: