Image Spam on the rise

Image-based spam is on the rise once again after hitting near-extinction late last year. Ralf Iffert and Holly Stewart of IBM's X-Force team detailed the phenomenon in a blog post last week, noting that the techniques used in the latest waves of image spam aren't any different than that seen during its height in 2006 and 2007, and that most spam blockers should be able to catch them. Still, the new rise in this old spamming practice indicates that spammers are once again pulling out all the stops to drum up business.

According to the two researchers, image spam saw its heyday in 2006 and 2007 when it got as high as almost 45 percent of all spam. It began to tank, however, in the second half of 2007, with 2008 practically putting a nail in the image spam coffin. The spamming method had dropped to only five percent of all spam in October of 2008 before the notorious McColo shutdown, subsequently taking image spam down to less than one percent of all spam in November.

This was apparently the calm before the storm, however. Image-based spam first hit five to 10 percent of all spam in March of 2009 before skyrocketing to 15-22 percent in April. Iffert and Stewart note that—unlike a couple of years ago—it seems to focus more on drugs and pharmaceuticals instead of stock trading (most likely due to the current financial crisis). Most don't contain any clickable Web links and rely on the user to manually type in a URL into the browser.

Why in the world would spammers decide to resurrect this technique, especially when it requires so much interaction on the user's end? "Perhaps they are trying to mask their URLs through these images ," wrote the researchers. "In their trial run near the end of March, did they see that some anti-spam systems were losing their edge when it came to image spam? We don’t think so. Are they simply running out of new ideas and rehashing old techniques? Maybe."

Because of the mysterious resurgence of image spam, Iffert and Stewart wonder whether other old 'n' busted spamming techniques will be coming back next, like PDF or MP3 spam. "Have we somehow hit a plateau of spam techniques? Who knows?" they wrote. "We can tell you that from the monitoring perspective, it all feels a bit strange. It's like sitting down to watch the storyline progress in your favorite TV show only to find that the directors have inexplicably substituted an 80's-style montage in its place."

Source:ComputerWorld