One in 10 UK web firms is sending unsolicited email to customers, contributing to a spam landscape that is spiralling out of control, according to spam monitoring firm Spam Ratings.
The firm's 12-month study of 10,000 web sites and 150,000 emails found that spam has increased dramatically, and that the main source of the messages is web sites.
The volume of spam coming from web sites rose by 110 per cent between October 2009 and September 2010, according to the firm, while the one in 10 sites that spam users are guilty of "five dangerous attacks a day".
Around 30 per cent of the spam is coming from third-party sites, suggesting that trusted parties are selling on personal information, while some of the most well-known brands are breaching marketing rules when dealing with customers.
One in five sites automatically opts users into sharing their details, including Argos, Ticketmaster.co.uk, Money Supermarket, Find A Property, Littlewoods and Woolworths.
"Spam is a nasty and dangerous disease that has turned into an epidemic in the UK. Web sites are the main cause and the main way the disease has spread," said Andy Yates, co-founder of Spam Ratings.
"Too many web sites sell data to third parties and are the source of the huge growth in unwanted and dangerous emails."
Some 40 per cent of these emails involve offers for pharmaceutical- or sex-related content, followed by finance at 35 per cent, phishing attacks at 15 per cent and malware or links to corrupt sites at 10 per cent.
Security firm Trend Micro reported earlier this month that the amount of spam coming out of Europe has pushed the region to the top of the company's global cyber crime rankings.
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