Just today, a virus hit one of my clients competitors. It was a trojan with the potential to unlock the door to their entire network. Many people asked me how it got into the network. Some asked me what a trojan was and if it was different from a virus. Others wondered about what kind of person would unleash a virus on other peoples computers.

It started me to thinking. If people knew more about virus programs, they might be better able to avoid being infected.

We will need some definitions before we can begin. Generally, viruses, trojans and worms are classified under the term malware. Malware is any unwanted program intended to cause harm to anothers computer or network.

A virus program corrupts or compromises your computer system. Normally, a virus can replicate, or duplicate itself without outside assistance.

As the original Trojan horse carried Greek soldiers into the City of Troy, so does a trojan program smuggle dangerous software into your network. Once inside this hidden program attacks your computer.

The program carried within the trojan is called the payload. This payload can be any program from a virus to a worm, or even anther trojan.

A worm attaches itself to other programs to spread throughout the computer network. It cannot replicate itself, but it can copy itself to other software.

All three have the potential to modify or destroy your data.

How do you get these nasty programs? The most common way is to download free software from the internet. Another way is to share files with others. Never put software into your computer you did not buy from a reputable dealer. File sharing is an open invitation to disaster.

Five things to do to keep your system clean:

1. Install a firewall on your network

2. Install, and update frequently, a quality anti virus program

3. Install and use a spyware and adware removal program every time you finish surfing the Internet. (Especially if you use Internet Explorer)

4. Download Mozilla, as an alternate to Internet Explorer.

5. DO NOT SHARE FILES WITH ANY ONE

If your business uses computers, and you store confidential information on your customers, you should have your network technicians conduct security scans regularly.

If you do not have a technician to do this for you, get one. It will make your network much more secure.

Finally, train your employees to be computer security aware. Your security program cannot succeed unless everyone joins and actively practices safe security.