Hackers have already exploited a vulnerability in Internet Explorer 7 (IE7) which was patched with a security fix by Microsoft only a week ago, it has been announced.

Known as MS09-002, the hole in the programming is being accessed through a specially-created Microsoft Word document which is emailed to users which are targeted by fraudsters.

The malware is also capable of self-updating, as a Trojan installs itself to the user's system when opened through email.

Jake Soriano, commenting on the phenomenon in his position as technical communications representative for Trend Micro, emphasised the importance of solid security systems to fight against such high-profile problems.

"IE7 is used by about every one in every four web users, a much larger share than previous versions of IE. This could explain why cybercriminals seem to be eagerly searching for more bugs," he told IT Pro.

Net Applications revealed at the beginning of the month that the popularity of IE has waned over the last few months in comparison to Mozilla Firefox and Apple Safari, although Microsoft's product still has market dominance.

According to a recent survey by Connect, the two biggest IT headaches for businesses were 'everyday hassles with IT' (37 per cent) and 'security concerns' (32 per cent).