The report revealed that only three percent of all spam collected last month could be classified as adult material. This included pornography, personal advertisements and relationship advice, as well as other messages containing or referring to products or services for people over the age of 18.
Emails offering health-related products and general goods and services both shared the top ranking spam category with 24 percent of unwanted email. Of all spam, 21 percent was related to financial products, 15 percent offered internet services and three percent were phishing scams, according to Symantec.
The monthly report also found that attackers are combining slanted text with other image spam obfuscation techniques to avoid detection. Rather than making changes to individual characters within the text of the image, the text is slanted at either an upward or downward angle to evade blocking techniques that rely heavily upon optical character recognition (OCR) or edge detection, according to the report.
Meanwhile, new research from Marshal reported that spam is at its highest levels ever, with an increase of 280 percent since last October.
The report, released Monday, said spam levels had jumped 30 percent in the past week with a sudden surge of unwanted emails coming from South Korea, China and Russia.
Image spam, which usually accounts for 15 to 20 percent of all spam, now makes up 35 percent of unwanted email, according to Marshal.
Bradley Anstis, director of Marshal research and product development, told SCMagazine.com that internet service providers (ISPs) are having a tough time keeping up with newer techniques – such an image spam – employed by spammers.
"One of the really worrying things in the Asia-Pacific region, with the increases we saw in October and November of last year, was that the ISPs had a terrible time keeping up. With the largest one, the email was shut down for four days," he said.
"We’re projecting similar levels of growth this year, and it could be a widening issue with ISPs just not being able to handle the pressure. They have to get more intelligent and try to address the problem as an industry."
Porn spam low; while spam hits record highs
By Fiona Raisbeck on Mar 8, 2007 1:06AM