More people are turning online to do their Valentine's day shopping, according to new research, but security firms have warned they need to take extra care as online criminals also increase their online activity around this period.

A poll of 250 Facebook and Twitter users showed that 37 per cent will buy their gifts online rather than from stores and, despite the credit crunch, will spend 12 per cent more online than they did last year.

The research, conducted by e-commerce analysis firm Avail Intelligence, also indicated that consumers had changed their buying patterns. Lovers said they were planning to give jewellery and holiday presents this year, rather than flowers or chocolate.

Pontus Kristiansson, Avail Intelligence chief executive, suggested that online retailers should take advantage of the spending after the retail casualties caused by the recession.

"Intelligent recommendations will create an enhanced shopping experience online," said Kristiansson. "Adopting a category management approach, as often seen on the high street, will attract new custom and have a positive impact on sales."

Meanwhile, security software vendors are warning Valentine's Day surfers to take extra care because there is likely to be a large increase in e-crime activity today.

PC Tools said that online criminals tend to employ a particular phishing technique in which infected Valentine's Day and love-themed files are delivered through emails or on social networking sites.

"Just as time-poor individuals are increasingly seeking alternative ways and new technologies to find love, cyber criminals recognise this trend and apply more advanced and sophisticated techniques to target the digitally active consumer," said Michael Greene, PC Tools vice president of product strategy.

"Cyber criminals attempt to trick consumers into clicking on hyperlinks that can either direct them to infected web sites or download infected files."

PC Tools reported in January on new variations of the Waledac worm, which delivers Valentine's Day-themed attachments, such as 'meandyou.exe' and 'onlyyou.exe' and then spreads using an infected computer's emailing networks.

It has the potential to spread to everyone the victim knows via unauthorised access to address books within their email, social networking or instant messaging applications.

This week PC Tools identified new malicious websites to which Waledac makers are distributing links, including 'loveprogramm.exe', 'ecard.exe', 'postcard.exe', 'lovekit.exe', 'mylove.exe', 'runme.exe' and 'loveexe.exe'.