First, it's a distinct minority of all spam, and filtering puts a frustratingly small dent in the problem. Second, the bad guys can easily adapt and are already doing so. A few months ago, a lot of the pump-and-dump stock spam messages were purely images, but now spammers often append a bunch of gibberish words or random sentences to the email by placing them underneath the image. Third, traditional antispam solutions can detect image-based spam reasonably well, responding to hashes of the images themselves and the fact that they are spewed out in bulk. Rather than blocking image spam wholesale, we can catch it using traditional antispam filters. So, your idea of filtering them is a good one, but nothing that will put a major dent in the glut of spam.
Dig Deeper on Emerging cyberattacks and threats
Related Q&A from Ed Skoudis
Learn how social networking sites compound the insider threat risk, and explore how to mitigate the threat with policy, training and technology. Continue Reading
At Black Hat 2006, researcher Joanna Rutkowska unveiled a piece of machine-based malware called the Blue Pill. But is it a serious threat to your ... Continue Reading
Wi-Fi on airplanes seems like it will be unavoidable in the future, but what security risks does it pose? In this security threats expert response, ... Continue Reading