Virus

Last updated 12 Oct 2009

A virus is a computer program or piece of code that can be put on your computer without your knowledge.  It may damage files stored on your computer without you even knowing that it was there.

Viruses can make copies of themselves so that they can sneak into other computers, either by travelling through the Internet, or hopping onto floppy disks.

There are thousands and thousands of different kinds of viruses that can all do different things to a computer.

Viruses are often disguised. The filename given to a virus may appear friendly at first, but do not be fooled!  A virus called “I love you” was disguised as an email attachment and was estimated to cause $10 billion worth of damage!

Once a virus is in a computer it can multiply and spread to other computers connected to the Internet.

A virus can get into your computer without you knowing. Anti-virus software can be used to protect your computer.

Types of virus

There are 3 main types of virus that can infect your computer:

  1. Trojan Horse: Trojan horses can claim to do something that might sound really cool and make you want to download it.  But, when you run the program on your computer, it might do something really un-cool, like erasing files on your computer. To protect yourself you should only download files when you are confident they are what they say they are.
  2. Worms: A worm is a virus that copies and spreads itself all over a computer network. Worms can drain a computer of its resources forcing it to shut down or not operate properly. Worms wriggle through security holes that exist in many programs to spread themselves to other computers. They will often use ports that are left open to gain access to a computer.
  3. Macros: A macro virus is written using the macro programming language found in Microsoft Office programs such as Word. They attach themselves to files and are activated every time the file is opened. A macro virus does its damage and then copies itself into other documents. A macro virus will spread every time you open that program.

Checklist

  1. Learn about the different types of viruses and how they work so you can be one step ahead of them.
  2. Only download files from the Internet if your sure they are what they say they are
  3. Be sure not to open suspicious email attachments. They may contain a virus!
  4.  Defend your computer by installing anti-virus software and a firewall
  5. Make sure to keep you anti-virus software up to date by downloading the latest patches on a regular basis.