The Internet Storm Center at the SANS Institute has a new diary entry reporting that the recent vulnerability in Adobe’s Acrobat and Reader software is being actively exploited. (This vulnerability has been assigned CVE-2010-2883 in the National Vulnerability Database.) You should be very cautious with any PDF files whose origins or contents are questionable.
As I noted in my previous post, the Microsoft Enhanced Mitigation Experience Toolkit [EMET] can be used to block this exploit on Windows machines. Directions and links are in that earlier post. So far, Adobe has not announced any timetable for a fix.