Most of you might be aware on what a computer virus is and what could it do to those computers that were infected. Basically, a virus is a program that could replicate itself without the knowledge of the user and it also has the ability to install or do some changes on your computer without your consent.

Viruses can be very lethal especially for big companies because it can freeze operations and could also damage infected computers. To know how deadly a virus could be, below would be some of the top viruses on the list that resulted to disaster.

I LOVE YOU - The "I LOVE YOU" virus estimated around $10 billion worth of damage. It spread via email and once you have it on your drive, it could copy itself and could stole passwords and send it to hackers.

My Doom - This virus spread via email and also by peer to peer file sharing. The virus forced google to shut down for almost a day. It infected many users because of its deceiving title like "Mail Delivery System" which many users would open especially if they are sending mails at that very moment.

Storm Trojan - The said virus... also spread via email and deceived users because of its subject "230 dead as storm batters Europe". The virus controlled the CPU's of millions of users at that time.

Nimda - it spread not just in emails but also in file servers and has the ability to automatically spread across the network. It actually hit the internet which caused many networks to crash during those times. The virus was actually controversial because it infected computers a week after the 9/11 attack.

The said viruses are only few of the viruses that existed which caused problems. We all know that the main goal of a virus is to infect the computers and spread it. Preventing a virus is not easy especially if we do not know what it looks like and what it does.

In order to prevent viruses, make sure to be cautious in opening and downloading emails especially those with attachments. If you are in doubt, it would be best to ask someone who knows computers if it is safe to open or download. Another thing, make sure that your computer's anti-virus is updated to at least give extra protection from viruses.

Many of us are not aware of the viruses that are around us but again, it would help a lot to be extra cautious in everything and most importantly, ask if you are in doubt.