Viruses vs Worms vs Trojan Horses - How to Avoid!


Viruses, worms, and Trojan Horses are malicious programs that can cause damage to your computer and information on your computer, slow down the Internet, and use your computer to spread themselves to your friends, family, co-workers, and the rest of the Web. The good news is that with an ounce of prevention and some good common sense you are less likely to fall victim to these threats. Think of it as locking your front door to protect your entire family.
What is a virus?

A virus is a piece of computer code that attaches itself to a program or file so it can spread from computer to computer, infecting as it travels. Viruses can damage your software, your hardware, and your files.

Virus :: Code written with the express intention of replicating itself. A virus attempts to spread from computer to computer by attaching itself to a host program. It may damage hardware, software, or information.
What is a worm?

A worm, like a virus, is designed to copy itself from one computer to another, but it does so automatically by taking control of features on the computer that can transport files or information. Once you have a worm in your system it can travel alone. A great danger of worms is their ability to replicate in great volume. For example, a worm could send out copies of itself to everyone listed in your e-mail address book, and their computers would then do the same, causing a domino effect of heavy network traffic that would slow down business networks and the Internet as a whole.
What is a Trojan Horse?

Just as the mythological Trojan Horse appeared to be a gift, but turned out to contain Greek soldiers who overtook the city of Troy, today's Trojan Horses are computer programs that appear to be useful software, but instead they compromise your security and cause a lot of damage. A recent Trojan Horse came in the form of an e-mail that included attachments claiming to be Microsoft security updates, but turned out to be viruses that attempted to disable antivirus and firewall software.

Trojan Horse :: A computer program that appears to be useful but that actually does damage.

Although viruses, worms, and Trojan Horses have very different characteristics, there are three main ways you can help protect yourself against all of them.

Step 1: Never open an e-mail attachment from a stranger.

Step 2: Never open an e-mail attachment from someone you know, unless you know exactly what the attachment is.

Step 3: Always keep your antivirus software up-to-date.

Step 4: Keep your Microsoft software current using our online resources.

Taken from the link: http://www.microsoft.com/security/articles/virus101.asp