Now PDF Is The Format For Spam Delivery

The never-ending game of whack-a-spammer-mole continues, with spammers now adopting PDF files as the new mechanism for delivering their junk mail. It seems like only yesterday we were talking about image-based spam, where the junk mail message was written in a GIF or JPEG file embedded in the letter. Now the junk mailers have been forced to change because spam blockers and detection mechanisms had gotten quite good at detecting image-based spam.<br><br>

As spam filters have improved, image-based spam has taken a hit. Secure Computing notes that image-based spam has dropped from the 30 percent range to just 10 percent of total e-mail volume in recent months.What's taking its place is a bigger nuisance. Spam in the form of attached PDF files has grown from just one percent in June to five or six percent of e-mail volume in just a month.