Some months ago I analyzed some PDF exploits that I received via SPAM mails. They contained the vulnerability CVE-2013-2729 leading to a ZeuS-P2P / Gameover sample. Back in June I received more PDF exploits, containing the same vulnerability, but in these cases it was a bit more difficult to extract the shellcode because the code was obfuscated.
more here...........http://eternal-todo.com/blog/CVE-2013-2729-obfuscated-pdf-exploits
more here...........http://eternal-todo.com/blog/CVE-2013-2729-obfuscated-pdf-exploits