Its impossible to explain why some people get a kick out of destroying other's computer systems. It’s the same with any kind of vandalism, perhaps they get a sense of power, or they may feel it’s an indication of their intelligence (which it is!), or maybe they just crave the notoriety (bragging often gets them caught). There’s absolutely no money in writing viruses. The money’s in developing Anti-Virus software. In fact, the idiots that write the viruses are solely responsible for making millionaires out of the AV developers.

    Destructive and damaging programs have been around since the early computers. They’ve caused different amounts of damage, from displaying a small annoying message on your monitor, to destroying your MBR or FAT and rendering your computer completely useless. But, they never used to replicate or clone themselves. They caused damage to the host computer and that was it. Distribution was the author's problem.

    Now, true 'viruses' can clone themselves. They can fill up your hard drive with garbage files and slow your computer down to a crawl. They can attach to files and keep copies of the original to fool 'anti-virus' programs. They can travel and infect other computers through floppy disks, CDs, shared network files, e-mail attachments and other files downloaded from the internet or over modem lines. They can 'morph' or change their signature (distinct properties or coding) as they infect, making it harder for anti-virus programs to detect.

    It is important to note that a virus does not destroy your actual hardware, just the programs, drivers and files associated with your hardware. However, with the popularity of 'Flash ROMs' being used on video cards, hard drives, NICs, and even your system BIOS, it's only a matter of time. A good anti-virus program is a must for your computer. But, don't think you can just install it and forget about it. There are hundreds of new virus signatures discovered every month. Most AV programs, like Mcafee or Norton Anti-Virus, will allow you to download and update your virus data and information files off the Internet for free. The virus data files available from these websites are updated every two-three months.

Something new, are the different online virus scanners and computer maintenance clinics. One I use is McAfee's. I have scanned and removed viruses using this online product. The virus information files are always up-to-date, and you don't have to worry about constantly downloading new signatures. Some may find it a little frustrating to set up at first, but hang in there, the product is well worth it.

Logic Bombs
    These are small but damaging programs that sit on your computer system and wait for a certain key combination, or a specific file access, or a certain date before releasing its payload.

Software Bombs
    This type of program generally releases its payload and causes damage as soon as it arrives on your computer.

Trojan Horses
    Trojan Horses, like their namesake, try to tempt or trick the user into activating the program themselves. They have innocent names, like 'IMPORTANT.EXE', 'README.EXE', 'URGENT.EXE', or appear to be a game or application. The user clicks on them and releases the payload.

Worms
    Usually found on intranets or internets, these files would gather information as they sat on the system. Maybe recording passwords
or access codes when they were typed in, or leaving 'back doors' open, allowing for unauthorized accesses.     Another type of worm is a file that just keeps replicating itself over and over. By constantly reproducing itself it can slow a computer or an entire network to a standstill.

    All these types of 'miscreant software' are often lumped together and called viruses. And, a lot of viruses do contain these in some form or another. However, a true virus usually has a 'host' file. In other words, it can attach itself to a file already on your system. It has the ability to clone itself. It can reproduce itself and infect other files or drives and computer systems. Viruses can also hide themselves from detection in several different ways.

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