New wave of PDF Spam

After months of almost no activity, managed service providers MX Logic reported a small wave of PDF spam emerge again. PDF spam was an extremely popular tactic for spammers back in June and July of 2007. On some of the most prevalent days PDF spam made up over 10% of overall internet spam volume.

Today’s wave is relatively small (less than 0.5% of spam volume) in comparison with the penetration that they saw back in mid-2007, but PDF spam has been almost completely non-existent since it waned back in late August.

According to Sam Masiello, director of threat management at MX Logic, it is not yet clear whether this is a small blip on the radar or if spammers are looking to get back into PDF spam on a wide scale, but PDF spam volumes having been near zero for the past 5 months, so this is certainly an interesting development in a tactic that had gone completely dormant.