PDF spam on the rise.

A large “pump-and-dump” stock spam campaign is underway, but rather than including the content of the spam in an image file, this campaign includes the spam content within a .PDF file. The stock spam is believed to be sent from Stration infected computers, as this spam campaign closely followed a new W32/Stration worm mass-mailing which contained a number of .PDF files, and Stration has been associated with pump and dump spam in the past. The current spam contains one or more .PDF files, has a randomly generated subject line and sender name, and a blank message body. The .PDF files contain images which look very similar to previous image based stock spam. Most of Belgian enterprises seems to be flooded by this new type of spam.
Please be careful before opening such type of email if it wasn't removed by your antispam solution.