If you want to learn how to crack software, you will need some tools and skills. One of the most popular tools for cracking is W32dasm, a disassembler that can show you the assembly code of any executable file. Another tool is Hiew32, a hex editor that can modify the binary data of any file. In this article, we will show you how to use these two tools to crack a simple software program.
Before we start, we need to clarify some terms and concepts. Cracking is the process of modifying a software program to bypass its protection mechanisms, such as serial numbers, registration keys, or online activation. A crack is a modified version of the original program that can run without any restrictions. A patch is a small file that can apply the crack to the original program automatically. A keygen is a program that can generate valid serial numbers or registration keys for a software program.
There are different types of protection mechanisms that software developers use to prevent unauthorized use of their products. Some of the most common ones are:
Checksums: These are values that are calculated from the data of a file and used to verify its integrity. If the file is modified in any way, the checksum will change and the program will detect it.
Cryptographic algorithms: These are mathematical functions that can encrypt or decrypt data using a secret key. The program can use them to hide important information, such as serial numbers or activation codes.
Anti-debugging techniques: These are methods that can detect if a program is being run under a debugger, a tool that can monitor and manipulate the execution of a program. The program can use them to prevent cracking or reverse engineering.
Obfuscation techniques: These are methods that can make the code of a program harder to understand or analyze. The program can use them to hide its logic or functionality.
To crack a software program, we need to find and remove or bypass these protection mechanisms. This requires some knowledge of assembly language, the low-level language that computers use to execute instructions. We also need some patience and creativity, as cracking can be a challenging and time-consuming task.
Let's see how we can crack a simple software program using W32dasm and Hiew32. We will use an example program called CrackMe.exe, which you can download from here. This program asks for a username and a serial number, and checks if they are valid. If they are not, it displays an error message and exits. Our goal is to crack this program so that it accepts any username and serial number.
The first step is to open the program in W32dasm and disassemble it. This will show us the assembly code of the program, which we can analyze and modify. To do this, we need to click on the Disassembler button and select the CrackMe.exe file. W32dasm will then load the file and display its code in the main window.
The second step is to find where the program checks the username and serial number. To do this, we need to look for strings or messages that are related to this functionality. We can use the Strings Reference button to see all the strings that are used in the program. We can see that there are two strings that are relevant: "Invalid Serial Number!" and "Correct!". These are the messages that are displayed when the serial number is wrong or right.
We can double-click on these strings to see where they are used in the code. We can see that they are both used in a function called CheckSerialNumber, which is called from another function called MainFunction. This function is where the main logic of the program is located.
We can double-click on MainFunction to see its code in detail. We can see that it does the following steps:
It calls GetDlgItemTextA to get the username and serial number from the text boxes.
It calls CheckSerialNumber to check if they are valid.
It calls MessageBoxA to display either "Invalid Serial Number!" or "Correct!" depending on the result of CheckSerialNumber. 9160f4acd4