Spammers are increasingly using the cover of legitimate website in an attempt to bypass IT security measures, a new survey has found.

According to a report by Commtouch spammers are using images taken from respectable sites to give their messages an air of authority.

They are also increasingly trying to pass themselves of as seemingly legitimate messages, such as welcome emails.

Amir Lev, Commtouch's chief technology expert, said: "Malicious emailers will use any freely available tool to their advantage, including Hotmail, Flickr, Blogspot and even Google and Yahoo calendar tools.

"Traditional content filtering tools are limited in the ways they can isolate the illegitimate emails that cloak their messages in legitimate content, since aggressive filtering will lead to false positives."

According to the report spam accounted for between 60 and 94 per cent of all email sent in the first quarter of the year.

Earlier this week, ITPro.co.uk reported that hackers are attempting to compromise trusted websites to increase the IT security threat they pose.

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) In a recent survey of SMEs for Connect, the two most important benefits of outsourcing were 'guaranteed response times' and 'allowing in-house IT staff to concentrate on more strategic issues'.