Protect your computer from dangerous viruses

May 02, 2002, vol. 24, no. 1
By Diane Luckow



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Sending and opening email attachments is akin to drinking and driving - it's an activity that once was commonplace but is now seen as completely unacceptable and dangerous.

That's the opinion of Alan Rothenbush, email virus expert with SFU academic computing services (ACS). He's also vociferous in his criticism of those who open email attachments without first checking to see if the sender did actually send the attachment.

That's because Rothenbush knows how much damage an email virus can cause and how much time it can waste. On any given day, he'll answer three to four panicked calls from virus victims, while a lineup of virus-ridden computers awaits a hopeful clean-up.

Frances Atkinson, associate director of ACS, says virus control requires the equivalent of two full time staff to block infected machines, deal with their owners, clean up the machines, help people set up filters in their email programs and work on server-based virus analyzers. “And that doesn't include the time that dozens of computer support people in various departments spend doing many of these same tasks,” she says.

“Right now there are close to 60,000 viruses out there,” says Rothenbush. “There are about 100 new viruses every week. You can download anti-virus updates hourly and still be at risk.”

The most devastating virus case Rothenbush can recall was several years ago when a middle-aged SFU researcher lost his life's work. The virus completely erased his hard drive, which he had never backed up.

Some viruses may erase or corrupt only some files. Still others are nuisances and embarrassing, scanning your hard drive for all email addresses, then mailing out bits of your private files to those addresses. After sending a random number of emails, some of these viruses will also corrupt or erase files on your hard drive. Some of the latest viruses are also capable of damaging the hard drive, requiring a costly repair.

Catching any of these viruses can mean days without your computer and without access to email, since academic computing may block email transmissions to the SFU server from computers they know are infected with viruses. During a two-week period in March, for example, ACS blocked eight on-campus machines and 62 home user machines. All but two of these machines were registered as SFU accounts.

Opening attachments, however, is no longer the only way to catch a virus. Many of today's viruses merely require you to click on and view the email.
There are even hoaxes masquerading as viruses. These send you an email telling you how to search for and erase a terrible virus from your hard drive. When you look for the file, you'll find it and erase it. The hoax? That file you've just erased belongs on your hard drive - and you're the guilty party. No virus required.

Then there is the problem of Internet viruses, or worms, and Trojan horses, both of which install software programs on your computer while you're viewing a web page or downloading games or information from a rogue site. Some also arrive via email.

These illicit programs permit human invaders to remotely control your computer when it's connected to the Internet. Some of these will maliciously damage your files, others will peer into your private information or watch your keystrokes - keeping track of your banking passwords and pass codes for example.

Theoretically, they could then use this information to control your computer remotely, initiating banking and stock trading transactions, for example, without your knowledge. While Robert Garigue, vice-president of information security for the Bank of Montreal group of companies, says this is theoretically possible, he notes that in practice, it is extremely unlikely.

He says it has never happened at the Bank of Montreal because of the security framework they have adopted. Should someone invade your bank account, there is little they can do, he says, but pay your bills or move money between accounts, since setting up and paying their own bills would leave an electronic trail.

Rothenbush, who never does his banking over the Internet, has found instances of this back door remote control software installed on machines belonging to SFU personnel, as well as evidence of activity suggesting that the software has been used in some way.

If you worry about such scenarios, says Garigue, “get a personal firewall and get a way to keep your viruses (protection) up-to-date. Then all of those scenarios go away.”

Since virus proliferation has become so intense this spring at SFU, ACS recently installed a virus analyzer on the mail server, which should help to reduce the problem.

With one million email messages arriving each week, this is a huge workload for the server, since the analyzer must examine the content of each message to find viruses before delivery.

Atkinson says this will mean delays in message delivery until later in the summer when ACS plans to install a more powerful mail server.
Regardless of this new analyzer, however, it's important to remain vigilant. As Rothenbush would say, it pays to practice good hygiene with your email.

Top ten tips to keep your computer healthy

Here are 10 tips for keeping your computer healthy and minimizing virus attacks:

1. Back up your hard drive regularly. This is your only defence against malicious viral damage.

2. Never open email attachments, even from someone you know, unless you have verified with the sender that they did send the attachment. Their computer could be propagating viruses without their knowledge or someone else may be using their email address. An email address, after all, is no better than the return address on an envelope.

3. If you must receive attachments, have them sent as .rtf (rich text format) which can be read by any word processing package. Or, have them sent in .pdf format which you can then read with Acrobat Reader. This is somewhat safer.

4. Don't send attachments - copy and paste them into the body of your email or convert them into .rtf or .pdf format.

5. Use a virus scanner to scan all attachments. Remember, however, that scanners are like flu shots - they don't always provide protection.

6. Don't use Microsoft Outlook or Microsoft Outlook Express - these are prone to viral infection.

7. Since you can now get a virus from just viewing a message, turn off the preview pane in Outlook Express, Netscape Mail or Eudora (under Options/Viewing Mail). The preview panes have effectively already opened the message for you. Also, in Eudora, turn off “Use Microsoft's Viewer”.

8. The safest local email program is Eudora, particularly version 3.

9. Some operating systems are more susceptible to worms than others. Windows 2000, Windows NT and Windows XP are the most susceptible. If you use any version of Microsoft Windows, visit the Microsoft website regularly to download patches and fixes. 10. Watch out when web surfing. A rogue site can send you a virus when you visit it.

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