I will provide a couple solutions to tutorial #9′s homework assignment. Keep in mind that there are an infinite amount of ways to crack this app, and this is only a small sample. If you found a way to do it on your own, congratulations. If not, don’t worry, we’ll be covering it all many times.
Beginner
R4ndom’s Tutorial #9: No Strings Attached
Introduction
In this tutorial we will be adding a new trick to our arsenal; what do you do if there are no usable string in the binary to search for? We will also be introducing a new R.E.T.A.R.D. rule 
In this tutorial (as well as the next) we will be studying a crackme called Crackme6 by “TDC”, included in the download. Overall, it’s not a tough crackme, but we will be doing some advanced analysis on it, preparing for future tutorials.
You can download the files and PDF version of this tutorial on the tutorials page.
So let’s get started…
The Reverse Engineers Toolkit
I remember when I first got started in reverse engineering. Well, let’s be honest. It was cracking commercial software. but I digress. Anyway, when one first starts getting introduced to this world, it doesn’t take long to learn a very important tenet: Tools are King. Most budding young crackers start getting the ‘tool-bug’ and start amassing as many tools as possible; it doesn’t matter that you don’t know what most of them do (or that half are actually viruses), just that it felt like the more tools one had, the better potential cracker they would be.
After the initial tool-buzz wears off you soon learn that most of those tools (and viruses) you amassed really aren’t that pivotal in day-to-day cracking (if there is such a thing). Hell, most of them you never really learn what the heck they do anyway! In fact, after you’ve been reverse engineering as long as I have (much longer than I like to admit) you eventually learn that you really only use a small subset of all the tools out there. Some you use regularly, some semi-regularly, and some rarely, tho all of the ones you use have a purpose.
It can be hard for a beginner to learn even what tools are out there, much less the tools that are really important and which aren’t. In order to help those who are interested in getting into reverse engineering (and yes, sigh, cracking) I have put together a list of what I consider the most important tools for really getting involved in RCE. I have arranged the list by several qualities, first of which is how often you would use them, followed by their importance and experience needed to use them, and finally where you can get them. If they are tough to find, I am hosting on this site so you can download them here. I have also included a description of what the tool does. And just because everything sounds cooler as an anagram, I am calling it
R4ndom’s “Reverse Engineering And Cracking Tools Of Note” or R.E.A.C.T.I.O.N.
I know it doesn’t change anything, but damn, it sounds cool!!!!
Now, before you begin flaming me with your “How could you not include tool X!!!” and “Tool Y SUCKS!!!”, please keep in mind that these are tools ordered by importance for *ME*. I know that everyone will not share my same viewpoints, but I hope to at least get the beginner started. And my ratings may be a little ‘loose’.
And lastly, don’t get me wrong, I still get excited when I learn of a new tool, even if it was programmed in 1997, Norton won’t even let me open it, it’s packed with Themida, and it’s called BackOrifice. Just the idea that it might be that long lost ‘secret’ program that let’s you unpack, un-protect, disassemble into proper English, debug and remove all copy-protection with the click of a single button, well, you never know. Some dreams you just don’t get over.