Malicious PDF Documents Explained

What makes a PDF file malicious? PDF designers and the PDF reader software architects never intended for files to be able to modify the operating system running the PDF reader. But security researchers and malware authors found ways to exploit PDF readers´ software bugs and to creatively use the PDF language, enabling them to produce PDF documents that execute arbitrary code. Embedded files are a good example of this design philosophy. The PDF language allows files to be embedded inside PDF documents.PDF reader software designers have begun using Windows security features such as data execution prevention (DEP) and address space layout randomization (ASLR) to prevent exploits from executing.