PDF malware analysis links

http://resources.infosecinstitute.com/analyzing-malicious-pdf/

http://digital-forensics.sans.org/blog/2009/12/14/pdf-malware-analysis/

https://blog.malwarebytes.org/intelligence/2013/08/the-malware-archives-pdf-files/

http://zeltser.com/reverse-malware/analyzing-malicious-documents.html

http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/the_rise_of_pdf_malware.pdf

http://blog.didierstevens.com/2008/04/09/quickpost-about-the-physical-and-logical-structure-of-pdf-files/

https://www.blackhat.com/presentations/bh-europe-08/Filiol/Presentation/bh-eu-08-filiol.pdf

http://blog.spiderlabs.com/2011/09/analyzing-pdf-malware-part-1.html