Receiving or sending emails that are affected with a virus or a worm can be very embarrassing. That is the funny thing about these viruses and worms, they almost always come from people you know, and they never have a clue what they have sent to you. It can also come through as spam messages. There is nothing that will readily mark these emails as viruses or worm suspects. Once you open the attachment the virus attacks your computer. Some so quietly that you never even know it is there hiding in your computer. Others come in raging, immediately changing or even erasing information on your computer.
Viruses spread themselves from computer to computer by attaching itself to files. Most viruses cannot spread until you physically open the files. So, when you share files or send infected attachments through email, you are inadvertently spreading the virus to other computers. Once the file has been opened, every time you send that particular file, it infects whomever you sent it to.
Worms are very similar to a virus. This is probably why many people confuse the two. A worm will attach itself to anything that will enable it to travel without human help. A worm will multiply once on your computer and send out thousands of its self and cause mass destruction. Once attached to your computer it will send a worm to every contact in your address book, their contacts and then their contacts. Creating a devastating chain that infects everybody’s computer it comes in contacts.
Your best defense against worms and viruses is to keep your computer system up to date and your anti-virus up to date. Although most anti-virus software will not always catch everything, it will go a long way to stopping most of the harmful viruses and worms. However, the best defense is to never open an attachment or emails that you do not know who the sender are, or are not expecting an attachment from that person.