OllyDbg is a 32-bit assembler level analyzing debugger for Microsoft Windows. This machine level debugger is created by Oleh Yuschuk for the 80×86. OllyDbg traces registers, recognizes procedures, loops, API calls, switches, tables, constants and strings. These features can be utilized to understand how an application internals.
Introduction
Ollydbg mainly has 4 windows in the default layout. CPU Window, Registers, Memory Stack and HEX Dump window. We will be working on CPU window most of the time.
A set of 3 tutorials illustrated here explains on how effectively can OllyDbg be used to identify the security holes and to ensure that the code written is healthy.







