Worms are malicious software programs that are capable of copying themselves from one computer to the next, and the term worm was first used in this context in a 1975 novel by John Brunner entitled The Shockwave Rider. In the book, the worm was designed to gather data from a computer network run by evil men who were gathering electronic information and attempting to spread their idea of conformity throughout the population.
There are three main types of malicious program commonly found today, and these are worms, viruses and Trojan horses. Unfortunately, these three programs are often confused, and the terms used interchangeably, but they are not in fact the same thing.
A virus attaches itself to another program or file and is spread as that file is passed from one computer to the next. Viruses are generally attached to executable files and will not do any harm unless the executable file is run. One very common way for viruses to spread is as an attachment to an email. As long as the attachment is not opened the virus cannot do its work and it can simply be deleted from your computer.
A Trojan horse is a clever software program that is designed to trick you into installing it on your computer. Essentially, it masquerades as legitimate software from a trusted source, and indeed it is often attached to a useful piece of software that you want to install. One particular danger from the Trojan horse is that it can be used to create a back door into your computer so that the creator can access personal information without your knowledge.
A worm is a little bit like a virus, except that it does not require any human intervention for it to start working. Worms normally exploit security holes in a piece of software, or in your computer’s operating system, and are not only easily spread across a computer network, but also have the ability to replicate themselves many thousands of times. Worms are particularly dangerous because, once they start replicating, they can take up so much of your system’s resources, or a network’s bandwidth, that whole computer networks can literally grind to a halt.
The easiest way to protect yourself from computer worms is to make sure that they do not get into your system in the first place, and that means doing two things.
First, you should guard against worms exploiting security holes in software and operating systems by ensuring that your programs and system are kept up-to-date.
Second, you have to try to keep those computer worms out of your system by ensuring that you are running a strong firewall program.
Anti-virus and anti-spyware programs may be able to help if your computer does become infected, but this is one case in which prevention is a much better solution than trying to find a cure.