Twenty years ago the typical hacker was a bedroom-based teenager with an IBM clone 386 PC, a dial-up modem, whose goal was to gain geek kudos by infiltrating and disrupting an unsuspecting corporate computer system.

Today's more scary incarnation, says Owen Johnston of security company Blue Coat Systems, is a very smart IT graduate, probably living in Eastern Europe, who is in the hacking business to make money - lots of money.

"They're not there to destroy things, they're there for economic reasons," said Johnston.

"They're there to monitise something. They're not there to break systems but they're there to be invisible. It's not about destroying you but about getting your data - understanding your identity, getting your credit card information. Getting into your system so they can get information and monitise that somehow."

While most of us are savvy enough to brush aside the so-called Nigerian email scams - unsolicited requests for bank account details made with a promise the sender will deposit untold riches in return for helping them to launder some newfound wealth - the horror stories of stolen identities and fraudulent credit card transactions continue to flood in.

Johnston said the average computer user's increased susceptibility to being stung by an online scam was related to the way our use of the internet has evolved in recent years.

We're spending more time online and the rise of social networking, and the ease with which anyone can publish content to the web means we seldom think twice about clicking a link, especially if we think it will lead us to a page authored by a friend.

At the same time the richness of multi-media content and technological sophistication behind web pages has changed significantly, Johnston said.

Increasingly complex and invisible programming code has transformed the internet from a simple bulletin board displaying text and the occasional picture into an exciting, interactive platform.

The downside of the sophisticated applications now embedded in the pages we load into our browsers is that they can provide deep cover for malicious content that can lurk on your PC long after you have moved on from a particular website.

"We've all been trained that if we click 'OK' or 'yes' [when invited to visit a particular web page or download something when we get there] we'll get cool content. Everything's become links ... and those links can deliver some pretty bad stuff," Johnston said.

"The whole aim [for the scammers] is to get people to click on a link and they're becoming very clever about how those links look," said Jeremy Hulse of M86 Security.

M86, a New Zealand-founded security firm previously called Marshal, this month bought Finjan, another security company specialising in spotting and deflecting dodgy websites before their content is loaded on to a user's browser.