Book excerpt: Going beyond the issues of analyzing and optimizing programs as well as creating the means of protecting information, this guide takes on the programming problem of how to go about disassembling a program with holes without its source code. Detailing hacking methods used to analyze programs using a debugger and disassembler such as virtual functions, local and global variables, branching, loops, objects and their hierarchy, and mathematical operators, this guide covers methods of fighting disassemblers, self-modifying code in operating systems, and executing code in the stack. Advanced disassembler topics such as optimizing compilers and movable code are discussed as well, and a CD-ROM that contains illustrations and the source codes for the programs is also included.