The copy protection mechanism often involves a process in which the software checks whether it should run and, if it should, which functionality should be allowed. The following sample shows a way of bypassing or removing the copy protection in order to use the product without extending the trial duration or, in fact, without purchasing the full version. The vendor stipulates a time restriction on the beta software in order to avoid license misuse and to permit the product to run only in a reduced-functionality mode until the user registers. In copy protection, the user is typically obliged to register the product before use. A familiar type of restriction built into software is copy protection, which is normally forced by the software vendor in order to test the robustness of the software copy protection. When the source code is not provided, it is still possible to patch the corresponding software binaries in order to remove various security restrictions imposed by the vendor, as well as fixing the inherent bugs in the source code. It is expected that the machine is configured with the following tools: Thank you for reading, Have a great day.The security researcher must have a rigorous knowledge of assembly programming language. However, you can find its right password by putting breakpoints and analyzing the ASCII dump that got created in the software. There are many ways to do it this is just the beginner level. Now, test your EXE again to see if it is working or not and if it gives the direct Right password message or not. So, what we will do here is that we just skip that logic by putting nop – non operation, by selecting that jump > right click > Binary > Fill with Nop. Now, we will find out the two jumps that actually make the comparison and matching for our name and password with its logic. Once we find that, we have to check out if it's calling convention code - A jump. We are finding the string – Right Password. Now, we will start to debug, so that we can find the exact referenced string to work out. To understand in an efficient way, try this link: x86 Instruction Set Below, I have shown the reference architecture of X86 registers which are quite useful while dealing with assembly language. The source code you see is X86 assembly language and might be messy if you work it for the first time. We will find those jumps and make them non-operational, that will simply surpass the matching details and print the right password message.Īs you can see, the EXE file is loaded in the software. We will upload this EXE in OllyDbg, then we will debug this file so that we get the source code where we can analyze the code with the help of the right jump conventions in the assembly language. Emphasis on binary code analysis makes it particularly useful in cases where source is unavailable. OllyDbg is a 32-bit assembler level analyzing debugger for Microsoft® Windows®. Now, what we are going to do is that we will simply try to surpass this whole wrong password thing to – Right Password with the help of OllyDbg. And, if you get matched with the correct details, you crack the EXE otherwise – nice try !Īs you can see in the above image, the details are wrong and that is why the wrong password message gets printed. In here, we are taking a keygen.exe that is having some requirement such as Enter you name, Enter your password. So, to remove such a possibility, we can include some meaningless extra code in your source code so that a reverse engineer cannot easily break the software and this is all about the obfuscation. Reverse engineers analyze your source code in assembly language and try to manipulate that source code using debuggers and by that, it removes the security or licensing or maybe they make an alternative software. Obfuscation is a complex term which is nearer to reverse engineering, that shows you the way to secure your source code from reverse engineering. The other aspect of this is how to reverse engineer any EXE to crack the licensing problem in the software. To start with obfuscate, we are taking one reverse engineering tool, which is OllyDbg.
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