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How You Can Protect Your Computer Against Worms and Viruses

It is important to make sure that your computer is free of worms and viruses. Even ones that don't seem to cause damage can be dangerous.

They can flood networks with rubbish, making normal operations difficult - they are what we call denial of service attacks.

They make your computer more vulnerable to future attack, because every machine with a worm infection is broadcasting to the entire Internet that it can be taken over by anyone who cares to copy the method the worm used. Also some viruses and worms disable standard security measures, or install their own back-door services that allow other people to use your computer over the Net.

Not least, worms are always trying to infect other people's computers. This is embarrassing for us, because the victims phone up and complain. If it isn't fixed, some Internet sites might refuse to accept Birkbeck email. It might even get us involved in legal action.

  1. Back up your work. No computer is 100% reliable If there is something on your computer that you need or want to keep, make sure it is backed up by a copy on another machine, or a removable device such as a Memory stick, CD or tape. If you use shared storage on a network computer, such as the N: drive on ITS PCs, it should be backed up centrally - but if something is REALLY important to you, keep another copy yourself as well! Email inboxes and Windows desktops are not safe places to keep important files.
  2. Keep up to date with fixes and security patches. This is more important than ever nowadays. Recent Windows worms have almost all exploited known vulnerabilities. People who kept their computers up to date with fixes were safe. Most people didn't, and weren't. Don't assume that home computers are safe - any machine which sends or receives email, or is ever connected to a network even for a few seconds, can be vulnerable.
  3. Always use a virus scanner and always remove viruses and worms if you find them. Keep up to date with virus detection files. See previous page on protecting personal equipment.
  4. Keep up to date. Whenever possible use recent versions of software (especially Windows software).
  5. Ensure a personal firewall program is configured.  See previous page on protecting personal equipment.
  6. Don't get caught by spam. A large proportion - perhaps more than half - of email viruses and worms arrive in messages that get trapped by our spam checkers. Avoid opening mail marked as spam. Never pass spam on to your friends and colleagues, and don't get involved in chain letters or circular jokes.
  7. Avoid running scripts. Set up mail clients (such as Outlook) so they do not run scripts in incoming mail. Avoid "previewing" mail, that is opening an mail item whenever the cursor goes over its entry on the incoming mail list.
  8. Be wary of attachments. Only open or run email attachments if you know where they come from and what they are. Never open attachments on spam mail, or mail that seems to come form you but that you don't remember sending.
  9. Be careful of web links in email. Avoid opening web links on incoming mail unless you know what they are. Never follow web links on spam, or other mail from people you don't know.
  10. Don't make life harder for others. To help your colleagues and friends get into the habit of thinking about attachments and links before opening, make as little use of attachments as possible.