Didier Stevens (Microsoft MVP, SANS ISC Handler, GSSP-C, GCIA, GCIH, GREM, Wireshark Certified Network Analyst, CISSP , MCSD .NET, MCSE/Security, MCITP Windows Server 2008, RHCT, CCNP Security, OSWP) is a Senior Analyst (NVISO https://www.nviso.be). Didier is a pioneer in malicious PDF document research and malicious MS Office documents analysis and has developed several tools to help with the analysis of malicious documents like PDF and MS Office files.
Didier is an active handler at https://isc.sans.edu. He also writes informative malware analysis contents on his personal blog http://blog.DidierStevens.com. You can also find his software http://blog.didierstevens.com/my-software and videos http://videos.DidierStevens.com