Four weeks ago, the opportunity to learn something about Reverse Engineering presented itself, I was asked to analyze and, if possible, modify a DOS executable. I saw this as a great excuse to tune my skills in assembly, so I began to search for a tool fitted for this task and as a main goal, I wanted to teach myself how to use it.
A few searches lead me to Radare2. At that point, I had already heard about IDA, Ollydbg, Hope and gdb but I had never used any of those tools, except gdb (during college).
Not knowing anything (practical) about Reverse Engineering, I couldn’t jump right into an executable with probably hundreds of lines, so I needed some exercises to get used to this tool, and that was how I found about Crackme exercises by IOLI. Later on, after read the Radare’s manual, I discovered that the authors also recommend this series of exercises as a practice.
Through the next posts I will document my solution to the Crackme exercises and at the same time learn something NEW!