Metasploit

Using Immunity Debugger to Decipher NOP Shellcode

Debuggers offer a window into the running state of a program, including assembly instruction flow, memory contents, and exception details. Penetration testers leverage debuggers on a regular basis to identify zero-day vulnerabilities and to understand how an application works and how to attack it. A number of debuggers are out there, but our personal preference going forward (and used in later chapters) is Immunity Debugger. We recommend that you take a look at the basics of Immunity Debugger before proceeding.

To understand what a NOP slide does, let’s use a debugger to look at how the NOP shellcode in the preceding example works. On your Windows XP target, download and install Immunity Debugger ...