Just as a blatant attempt to get more people to read my tutorial, I have decided to start a sweepstakes. Whoever the first person is who can answer the Insanely Difficult Extra Credit problem at the end of tutorial #10 will win a free iPud*. So download it now!!!!
Please see official rules after the jump…
In this tutorial we will be discussing the different levels to patching a binary. This tutorial is a little on the long and detailed side, but we will be covering a lot of ground, some of which is not that easy. I wanted to give you an example of deep analysis on a binary, and what it entails. You may not understand a great deal of it, but it will give you a good overall view of reverse engineering. This way, in future tutorials, you will have a frame of reference. We will be studying the same crackme as last tutorial, Crackme6 by “TDC”, included in the download.
You can download the files and PDF version of this tutorial on the tutorials page.
Overall, it’s not a tough crackme as we saw in the last tut, but we will be doing some advanced analysis on it, preparing for future tutorials. So sit back, grab a coffee/cigarette/candy bar/hypodermic needle, whatever gets you going, and let’s get started…
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.
Seeing as I hadn’t gotten to that page in the manual that sets up user’s permissions, I was the only one who could previously post on the forum. Normally, I kind of like this feature, but then I realized I already had this: It’s called a blog. So I have gone through several more pages of the instruction manual and have now added wonderful features to the forum, stuff like being able to log in, reading a forum entry, and posting a post. Along the way I even added support for avatars (whatever they are) and signatures (whatever they are). I even added the option of everyone moderating their own posts, thereby relieving me of the duty!
Just kidding. I hope…
NAME: “Forum”
BORN: Yesterday
WEIGHING: Not very much.
If you would like to join in on this joyous event, please go to http://TheLegendOfRandom.com/forum/ or click the “Forum” menu item at the top of any page.
Now, if you have a question or comment, you don’t need to leave it as a comment and hope someone sees it. Just go to the forum!
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…
In this tutorial we are going to be adding a menu item to a binary. There are many uses for adding a menu item to an existing binary. Perhaps you find yourself typing the same phrase over and over – it may be a lot easier just to make it a menu item that when selected, pasted that phrase into your app. Maybe you would like to add a little sunshine to a co-workers day by adding a “UNDO” menu item, that instead deletes the file, reminding him or her of the importance of not taking the undo button for granted. There are many reasons for adding a menu item, but most of all, it’s just interesting how it works
Now we’re gonna look at a crackme that’s just a little more challenging. It is called Crackme3.exe. We will also learn some new tricks.
You can download the files and PDF version of this tutorial on the tutorials page.
Go ahead and start up Olly and load in the crackme. It should load, analyze and pause on the first line:
So let’s run this and see what we have:
Is it me or are you starting to feel less human too?
Captchas, or those annoying pictures at the bottom of forms that are supposed to prove that you are human, are everywhere. CAPTCHA stands for “Create A Picture to Chastise Humanity’s Aptitude”. You know what I’m talking about, you must enter the displayed text that looks like a drunk epileptic wrote during their first Taiwanese writing lesson and then was photocopied 13,000 times before photographed by a broken Polaroid and emailed to the site over dial-up. And I’m not human unless I can read this? No one can read this, not even the drunk epileptic who first wrote it!
The ironic thing is that Captchas are becoming so difficult to read, we’re going to need to start using computers, with their vast processing powers, to decipher these images, thereby proving that computers are actually human and we are not. The social networking sites will then be overrun with computers and we all know that computers have no personality (which I guess the Captchas were originally there to prevent) and pretty soon us humans will be caste into doing what the computers think is boring remedial work, which I can only guess is coming up with more Captchas…
Welcome to Part 7 of of R4ndom’s tutorials on Reverse Engineering. This time, we will be cracking two crackmes; one to re-iterate last tutorial’s concepts, and one that we are going to have a little fun with In the download of this tutorial, you will find these two crackmes as well as the program “Resource Hacker” that we will be using on the second crackme. You can also download this tool on the tools page.
You can download the files and PDF version of this tutorial on the tutorials page.