Leader: Online crime - new tools, old tricks

Who owns the internet? No one - but criminals would have it otherwise.

This week virus writers took a further step into the underworld when they released a Trojan horse program that holds computer data hostage unless you pay $200. The program infects computers through a weakness in Internet Explorer. It finds files with certain extensions, '.doc' for instance, encrypts them and then demands you pay up or never see your data again.

The good news is security companies have seen only a few reports of this sort of exploit. The bad news is it's only a matter of time before this trick becomes commonplace. Virus writers looking for fame and glory are in much smaller numbers these days as criminals have moved onto their patch and are designing malware for profit.

As more of society finds its way onto the internet, crime is also learning the weaknesses in the web. Now these Trojan attacks allow crooks to demand money without setting foot in your house or even your country.

But remember - crime hasn't changed. The difference is in the tools criminals use.

In this latest incident using a Trojan is new. And remotely holding computer data hostage is new. But ransom is an old crime.

The internet is just the latest playground for less law-abiding citizens. After all, the internet provides opportunities to everyone - and criminals are some of the most innovative people around. They have tried extortion with denial of service attacks on websites, blackmail by threatening to plant child pornography on people's computers and are now holding personal computer files to ransom.

Unfortunately, given that UK police resources are creaking under a two-year backlog of computer crime cases, criminals are probably not feeling too much heat.

It all serves to underscore the importance of law enforcement and computer security companies using their own imagination and powers of innovation to stay one step ahead of these ever-more-clever online troublemakers.