The above description is profile of average computer-virus writer, according to Jan Hruska, chief executive of British-based Sophos PLC, world's fourth-largest anti-virus solutions provider.

"They have a chronic lack of girlfriends, are usually socially inadequate and are drawn compulsively to write self- replicating codes. It's a form of digital graffiti to them," Hruska added.

To create and spread cyber infections, virus writers explore known bugs in existing software, or look for vulnerabilities in new versions.

With more and more new OS (operating system) versions, there will be more new forms of viruses, as every single software or OS will carry new features, and new executables that can be carriers of infection.

Executables are files that launch applications in a computer's operating system, and feature more prominently in new platforms like Microsoft's Windows 2000 and Windows XP than they did in older DOS or Windows 3.1.

Virus writers also share information to create variants of same infection, such as Klez worm, which has been among world's most prolific viruses.

The Klez, a mass-mailing worm that originated in November 2001, propagates via e-mail using a wide variety of messages and destroys files on local and network drives.

But news gets worse. Recent events have uncovered what may be a new trend: spammers paying virus writers to create worms that plant an open proxy, which spammer then can use to forward spam automatically. Many suspect this occurred with SoBig virus.

The Sobig worms, began spreading in early part of 2003. The unusual thing about them was they contained an expiration date and were given a short life cycle to see how features worked in wild.

Begin with a needs analysis. Define your business goals, prioritise them, and then assess what features or tools are needed to help you reach those goals. At a later point, once pricing research is under way, you can then assess price of features relative to priorities of goals and come up with basis of an intelligible cost-benefit analysis.

Start by examining nature of your site. Is it a portal? A marketing exercise? An e-commerce site? These questions will set outer boundaries for defining type of system you need. A marketing site will demand far less from a system than a portal. Moreover, security, support, and data integrity issues will be dominant concerns for any firm involved in e-commerce.

Consider not only your short term needs but also your long term goals. Many of systems that are in market today are modular. This allows you flexibility to start with only features you need to meet your short term goals, then to expand system as justification (or necessity) develops.

Accordingly, look at modules offered by vendor and make an assessment of whether system will suit your planned future expansion. It is foolish to try to build it all at once as cost will be high and time line extended. It is better to start conservatively with a modular system that you can grow into.

When shopping for systems, it is best to approach vendor with a shopping list of features that you require/desire. Mature systems will offer more modules, but make sure you demo modules you are interested in, as implementations of similar functionalities tend to vary more than you might expect.