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, once having found holes in a program, how to go about disassembling it without its source code. Covered are the hacking methods used to analyze programs using a debugger and disassembler. These methods include virtual functions, local and global variables, branching, loops, objects and their hierarchy, and mathematical operators. Also covered are 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.