Do you know that many common file formats can be (and have been) abused by attackers to deliver malware or to gain initial access ?
This series of articles describes each of those formats, dives into attack techniques and obfuscation techniques, and provides references to relevant articles and tools.
This article describes the PDF file format, related security issues and useful resources
This article describes the Microsoft Office 97-2003 legacy/binary file formats (doc, xls, ppt), related security issues and useful resources. ...
This article describes the Microsoft Office Open XML file formats (docx, xlsx, pptx), related security issues and useful resources. [WORK IN PROGRESS] ...
This article describes the OpenDocument file format (ODF), related security issues and useful resources. [WORK IN PROGRESS] For now, see http://www.decalage.info/opendocument_openxml