Whether as home users or office workers, humans remain the weakest link when it comes to IT security. Sophos expects hackers to exploit this fact and predicts social engineering to rise in 2007.

"The biggest problem in 2006 was not how we upgrade an OS [operating system] or browsers, but how we upgrade people's brains – their knowledge in computing," said Graham Cluley, senior technology consultant for security solutions provider Sophos.

Cluley said this applies not only to home users but also for business users, such that even when people are hit badly or have come across various kinds of 'malware' already, they still have the tendency to be careless in what they click on or download from the internet.

Social engineering has become a household term for quite some time as hackers and spammers have increasingly used creative means to build on human vulnerability by appealing to their emotions or playing on their curiosities.

"The problem really is how we could get the users to act sensibly and think before they click; it's not something that technology can solve," Cluley said.

He added that "computer common sense" does not seem to be very common after all. This is, however, understandable because PCs are very complicated, especially for home users, he noted.

One trend that Sophos has observed of late is that attacks are becoming more focused. In China, for example, more than 50 percent of computer malware is designed to steal passwords mostly from online games. In Brazil, on the other hand, 78 percent is designed to steal banking passwords or 'phishing'.

"Social engineering is really a technique that will work for a very long time against people; it will always be a problem. All we can do is educate and raise awareness on security issues," Cluley said.

He added that more spammers and hackers are increasingly doing it for profit and not merely as a hobby or in order to gain notoriety because "people realise it's a physically easier task than robbing a bank".