Backdooring PDF Files

Updates: 20/09/07 PDPs PDF URI Parsing Vulnerability Recently, there has been alot of hype involving backdooring various web technologies. pdp (arcitect) has done alot of work centered around this area. I saw Jeremiah Grossman mention PDFs being BAD, however, I was unable to easily locate any practical reasons as to why. I decided to investigate this a little further.