IT contractors are sometimes called upon to help defend a business against cyber attacks, and according to internet security firm Norton, the people behind malware are always evolving their strategies.

Dan Nadir, senior director of consumer products at Norton, said cyber criminals are continuing to tweak their attacks based on the latest trends, often based on whatever has been popular on social networking sites.

"Additionally, the small screen of a mobile device, and the fact that many sites reformat content to make it mobile-friendly, makes it more difficult for the average user to tell the difference between a legitimate and a fake site," he added.

The comments come soon after a report from online intelligence service Experian Hitwise found that social media has become the single biggest online activity in the UK for the first time.

It is estimated by Norton that cybercrime will cost the British economy nearly £2 billion in 2011, which could see more firms hiring IT contractors to mitigate the threat.