Definition on Common Terms

What is a Virus?
A virus is a program or a piece of code that can copy itself and infect a computer without your permission or knowledge to cause an unexpected and usually negative event.

What is a Worm?
A worm is a virus that sits in the active memory of a computer and duplicates itself. It may send copies of themselves to other computers, such as through email or Instant Messaging.

What is a Trojan Horse?
A Trojan horse program is a malicious program that pretends to be a benign application; it performs malicious functions that allow unauthorized access to the host machine without your knowledge. Trojans are not viruses since they do not replicate, but Trojan horse programs can be just as destructive.

Many people use the term to refer only to non-replicating malicious programs, thus making a distinction between Trojans and Worms.

Prevention Tips

1. Do not open any files attached to an email from an unknown, suspicious or untrustworthy source.

2. Do not open any files attached to an email unless you know what it is, even if it appears to come from a dear friend or someone you know. Some viruses can replicate themselves and spread through email. Better be safe than sorry and confirm that they really sent it.

3. Do not open any files attached to an email if the subject line is questionable or unexpected. Always ensure that the files are scanned by your anti-virus software before opening them.

4. Delete chain emails and junk email. Do not forward or reply to any of them. These types of email are considered spam, which is unsolicited, intrusive mail that clogs up the network.

5. Do not download any files from website/source that you do not trust.

6. Exercise caution when downloading files from the Internet. Ensure that the source is a legitimate and reputable one. Verify that an anti-virus program checks the files on the download site.

7. Update your anti-virus software regularly. You may also need to update the anti-virus software scanning engine as well.

8. Back up your files on a regular basis. If a virus destroys your files, at least you can replace them with your back-up copy. You should store your backup copy in a separate location from your work files, one that is preferably not on your computer.

9. If you are in doubt about any potential virus-related situation you find yourself in, you may consult/report the virus to your anti-virus software vendor.