Secure Computing Corp said it had picked up a 200% increase in the level of image spam it has monitored over the past few months. Image spam is being used by hackers to bypass spam screening software that tests messages for spam based on keywords. It is much harder to detect with conventional spam-filtering and blocking technologies and typically consumes much more bandwidth and storage than text-based attacks.
Secure Computing said it can now account for 30% of all spam and one in every four messages circulating on the internet.
Meanwhile, MessageLabs has warned of a sudden increase in spam levels on the back of a huge rise in botnet activity and the latest outbreak of the Warezov virus, which deploys an aggressive spam Trojan.
Mark Sunner, CTO with the content security service provider, said that although spam activity is always seasonal, the end-of-year detection rates suggest activity is particularly high and particularly early. We’ve seen unprecedented levels in October, he said.
In the MessageLabs Intelligence Report for October 2006 the company noted that the spam-sending SpamThru Trojan has significantly increased spam levels to almost three out of every four emails. In October, the global ratio of spam in email traffic from new and unknown bad sources was 72.9%, the sharpest rise in spam levels since January 2006.
Sunner said phishing attacks are also becoming more sophisticated, with some attacks being detected that contain personal details of targets such as names and addresses. He suggested that the popularity of social networks like Link-Me and Myspace is only aiding and abetting the malware writers.
