How to Use OllyDbg to Bypass or Generate License Keys for Complex Software Protection
How to Crack Software Using Ollydbg on Complex Software Protection
Software cracking is an act of removing or bypassing copy protection from a software, usually to use it for free or access its premium features without paying for it. Software cracking can be done for various reasons, such as curiosity, challenge, learning, or profit. However, software cracking is also illegal in most countries and can expose you to malware, viruses, legal issues, and ethical dilemmas.
How To Crack Software Using Ollydbg On Complexl
One of the most popular tools for software cracking is Ollydbg, a 32-bit assembler level debugger for Windows. Ollydbg allows you to analyze, modify, and patch the binary code of any executable file, making it ideal for reverse engineering and cracking software. Ollydbg has many features, such as tracing registers, recognizing procedures, API calls, switches, tables, constants, and strings, setting breakpoints, searching for code patterns, and more.
However, not all software is easy to crack. Some software developers use complex protection schemes to prevent or deter cracking, such as encryption, obfuscation, anti-debugging, checksums, online activation, hardware locks, dongles, etc. These protection schemes can make it harder to find and modify the code that controls the licensing or registration of the software.
In this article, we will show you how to crack software using Ollydbg on complex software protection. We will guide you through the steps of downloading and installing Ollydbg and other tools, loading the target software into Ollydbg and analyzing its code, finding the protection scheme and locating the relevant code sections, modifying the code to bypass the protection or generate a valid license key, saving the patched software and testing it. By following this tutorial, you will be able to crack any software that uses complex protection schemes.
Step 1: Download and install Ollydbg and other tools
The first step is to download and install Ollydbg and other tools that you will need for cracking software. You can download Ollydbg from its official website or from other sources. Ollydbg is a shareware, but you can use it for free without registration. However, if you like it and use it regularly or for commercial purposes, you should register it by sending a filled registration form to the author.
Ollydbg is compatible with Windows XP/Vista/7/8/10. To install it, just unzip the downloaded file into any folder and run ollydbg.exe. You can also create a shortcut on your desktop or start menu for easy access.
Other tools that you will need for cracking software are:
A hex editor: A hex editor allows you to view and edit the raw bytes of any file in hexadecimal format. You can use it to modify the binary code of the target software directly or to compare different versions of the same file. There are many hex editors available online, such as HxD, Hex Workshop, WinHex, etc.
A disassembler: A disassembler converts binary code into assembly language instructions that are easier to read and understand. You can use it to analyze the logic and functionality of the target software or to create patches or key - generators. There are many disassemblers available online, such as IDA Pro, Ghidra, Radare2, etc.
A debugger: A debugger allows you to run the target software in a controlled environment and monitor its behavior and memory. You can use it to set breakpoints, step through the code, modify registers and variables, watch expressions, etc. Ollydbg is also a debugger, but you can use other debuggers as well, such as x64dbg, WinDbg, Immunity Debugger, etc.
A PE editor: A PE editor allows you to view and edit the structure and metadata of a Portable Executable (PE) file, which is the format of most Windows executable files. You can use it to change the entry point, import and export tables, sections, resources, etc. There are many PE editors available online, such as PE Explorer, CFF Explorer, Resource Hacker, etc.
A keygen: A keygen is a program that generates valid license keys or serial numbers for a software. You can use it to activate the software without cracking it or to create your own keygen for a software. There are many keygens available online for various software, but you can also create your own keygen using programming languages such as C, C++, Python, etc.
After downloading and installing these tools, you are ready to crack software using Ollydbg on complex software protection.
Step 2: Load the target software into Ollydbg and analyze its code
The next step is to load the target software into Ollydbg and analyze its code. The target software is the software that you want to crack. You can choose any software that uses complex protection schemes, such as encryption, obfuscation, anti-debugging, checksums, online activation, hardware locks, dongles, etc. For this tutorial, we will use an example software called CrackMe.exe, which is a simple program that asks for a license key and checks if it is valid or not.
To load the target software into Ollydbg, you need to do the following:
Run Ollydbg as administrator by right-clicking on ollydbg.exe and selecting "Run as administrator". This will give Ollydbg full access to the target software and its memory.
Click on File -> Open or press Ctrl+O to open the file dialog. Navigate to the folder where you saved the target software and select it. Click on Open to load it into Ollydbg.
Ollydbg will display the code of the target software in the CPU window. The CPU window shows the disassembly of the code in assembly language, along with the registers, flags, stack, memory dump, etc. You can use the toolbar buttons or keyboard shortcuts to navigate through the code, set breakpoints, run or pause the program, etc.
Before running the target software, you need to analyze its code and find out how it works and what protection scheme it uses. You can use various techniques to do this, such as:
Searching for strings: You can search for strings in the code that may indicate the type or location of the protection scheme. For example, you can search for strings like "license", "key", "serial", "activation", "registration", "invalid", "error", "crack", "debug", "encrypt", "decrypt", etc. To search for strings in Ollydbg, you can use Edit -> Find or press Ctrl+F to open the Find dialog. You can also use View -> Executable modules or press Alt+E to open the Modules window and double-click on any module to view its strings in a separate window.
Searching for patterns: You can search for patterns in the code that may indicate the type or location of the protection scheme. For example, you can search for patterns like "pushad; call ; popad;", which may indicate an anti-debugging technique that saves and restores all registers before and after calling a function that checks for debuggers. To search for patterns in Ollydbg, you can use Edit -> Find pattern or press Ctrl+B to open the Find pattern dialog.
Tracing calls: You can trace calls in the code that may lead to the protection scheme or its validation routine. For example, you can trace calls like "call ", which may call a function that checks or generates a license key or performs encryption or decryption. To trace calls in Ollydbg, you can use Debug -> Trace over or press F8 to execute one instruction at a time and follow any calls or jumps.
Analyzing imports: You can - analyze imports in the code that may indicate the type or location of the protection scheme. Imports are external functions or libraries that the target software uses to perform certain tasks. For example, you can analyze imports like "kernel32.dll", "user32.dll", "advapi32.dll", etc., which may contain functions that check for debuggers, manipulate registry keys, encrypt or decrypt data, etc. To analyze imports in Ollydbg, you can use View -> Executable modules or press Alt+E to open the Modules window and double-click on any module to view its imports in a separate window.
Analyzing exports: You can analyze exports in the code that may indicate the type or location of the protection scheme. Exports are internal functions or variables that the target software exposes to other programs or modules. For example, you can analyze exports like "CheckLicenseKey", "GenerateLicenseKey", "EncryptData", "DecryptData", etc., which may be part of the protection scheme or its validation routine. To analyze exports in Ollydbg, you can use View -> Executable modules or press Alt+E to open the Modules window and double-click on any module to view its exports in a separate window.
Analyzing resources: You can analyze resources in the code that may indicate the type or location of the protection scheme. Resources are data or files that the target software uses or embeds, such as icons, images, sounds, dialogs, menus, etc. For example, you can analyze resources like "LICENSE.TXT", "KEYGEN.EXE", "ENCRYPTED.DAT", "DECRYPTED.DAT", etc., which may contain license information, key generators, encrypted or decrypted data, etc. To analyze resources in Ollydbg, you can use View -> Executable modules or press Alt+E to open the Modules window and double-click on any module to view its resources in a separate window.
By using these techniques, you should be able to identify the type and location of the protection scheme and its validation routine in the target software. For example, in our CrackMe.exe program, we can find out that it uses a simple encryption algorithm to encrypt and decrypt the license key and compares it with a hard-coded value. We can also locate the code sections that perform these operations and set breakpoints on them.
Step 3: Find the protection scheme and locate the relevant code sections
The third step is to find the protection scheme and locate the relevant code sections in the target software. The protection scheme is the method or technique that the target software uses to prevent or deter cracking. The relevant code sections are the parts of the code that implement or control the protection scheme or its validation routine. You need to find these code sections and modify them to bypass the protection or generate a valid license key.
To find the protection scheme and locate the relevant code sections in the target software, you need to do the following:
Run the target software normally and observe its behavior and output. For example, you can run CrackMe.exe and enter any license key and see what happens. You will see that it displays a message box saying "Invalid license key!" if you enter a wrong key or "Valid license key!" if you enter a correct key.
Run the target software under Ollydbg and set breakpoints on the relevant code sections that you identified in step 2. For example, you can set breakpoints on the code sections that encrypt and decrypt - the license key and compare it with the hard-coded value. To set breakpoints in Ollydbg, you can use Debug -> Toggle breakpoint or press F2 on any instruction.
Run the target software under Ollydbg and enter any license key. Ollydbg will pause the execution when it reaches a breakpoint and show you the current state of the program. For example, you will see that Ollydbg pauses at the instruction that encrypts the license key and shows you the value of the key in the memory dump window.
Analyze the code and data at the breakpoints and try to understand how the protection scheme works and how to bypass it or generate a valid license key. You can use various techniques to do this, such as:
Modifying registers: You can modify registers in Ollydbg to change the values of variables or parameters that affect the protection scheme or its validation routine. For example, you can modify the EAX register to change the result of a comparison or a calculation.
Modifying memory: You can modify memory in Ollydbg to change the values of data or code that affect the protection scheme or its validation routine. For example, you can modify the memory dump window to change the value of a license key or a hard-coded value.
Modifying flags: You can modify flags in Ollydbg to change the outcome of a conditional jump or a loop that affects the protection scheme or its validation routine. For example, you can modify the ZF flag to change whether a jump is taken or not.
Modifying code: You can modify code in Ollydbg to change the logic or functionality of the protection scheme or its validation routine. For example, you can modify an instruction to change its opcode, operand, or address.
By using these techniques, you should be able to bypass the protection scheme or generate a valid license key for the target software. For example, in our CrackMe.exe program, we can bypass the encryption algorithm by modifying the code that calls it and replacing it with a NOP instruction (90) that does nothing. We can also generate a valid license key by reversing the encryption algorithm and applying it to the hard-coded value.
Step 4: Modify the code to bypass the protection or generate a valid license key
The fourth step is to modify the code to bypass the protection or generate a valid license key for the target software. This is where you actually crack the software and make it work without any restrictions or limitations. You need to apply the modifications that you found in step 3 and save them into a new file.
To modify the code and save it into a new file, you need to do the following:
Select the instructions that you want to modify in Ollydbg and right-click on them. Choose Binary -> Edit from - the context menu. A dialog box will appear where you can enter the new bytes that you want to write. For example, you can enter 90 to write a NOP instruction or enter the bytes of a valid license key. Click on OK to confirm the changes.
Repeat step 1 for all the instructions that you want to modify in Ollydbg. You can also use other tools, such as a hex editor or a PE editor, to modify other parts of the file, such as the entry point, the import and export tables, the sections, the resources, etc.
After modifying all the instructions and parts that you want, you need to save the changes into a new file. To do this in Ollydbg, you can use Edit -> Copy to executable -> All modifications or press Ctrl+A to open the Copy to executable window. This window shows all the modifications that you made in Ollydbg and allows you to save them into a new file.
Click on Right-click -> Save file or press Ctrl+S to open the Save file dialog. Choose a name and a location for the new file and click on Save. Ollydbg will create a new file with all the modifications that you made and save it into the chosen location.
You have now successfully modified the code to bypass the protection or generate a valid license key for the target software. You have also created a new file that contains these modifications and can run without any restrictions or limitations.
Step 5: Save the patched software and test it
The final step is to save the patched software and test it. The patched software is the new file that you created in step 4 that contains all the modifications that you made to bypass the protection or generate a valid license key for the target software. You need to save it into a safe location and test it to make sure that it works as expected.
To save and test the patched software, you need to do the following:
Copy or move the patched software from its original location to a safe location, such as a USB drive, an external hard drive, or a cloud storage service. This will prevent any accidental deletion or modification of the patched software by antivirus programs, system updates, or other users.
Run the patched software normally and observe its behavior and output. For example, you can run CrackMe_patched.exe and enter any license key and see what happens. You will see that it displays a message box saying "Valid license key!" regardless of what key you enter.
Compare the patched software with the original software and verify that they have the same functionality and features, except for the protection scheme or its validation routine. For example, you can compare CrackMe_patched.exe with CrackMe.exe and verify that they have - the same user interface and functionality, except for the license key validation.
Test the patched software on different devices and operating systems and check for any errors or compatibility issues. For example, you can test CrackMe_patched.exe on Windows XP, Windows 7, Windows 10, etc. and check for any errors or compatibility issues.
You have now successfully saved and tested the patched software. You have also verified that it works as expected and has the same functionality and features as the original software, except for the protection scheme or its validation routine.
Conclusion
In this article, we have shown you how to crack software using Ollydbg on complex software protection. We have guided you through the steps of downloading and installing Ollydbg and other tools, loading the target software into Ollydbg and analyzing its code, finding the protection scheme and locating the relevant code sections, modifying the code to bypass the protection or generate a valid license key, saving the patched software and testing it. By following this tutorial, you have been able to crack any software that uses complex protection schemes.
However, cracking software is not a simple or easy task. It requires a lot of skills, knowledge, patience, and creativity. It also involves a lot of risks, such as malware, viruses, legal issues, and ethical dilemmas. Therefore, you should be careful and responsible when cracking software. You should only crack software for educational or personal purposes, not for commercial or malicious purposes. You should also respect the intellectual property rights of the software developers and pay for their products if you like them and use them regularly or for commercial purposes.
If you want to learn more about software cracking and reverse engineering, you can check out some of the following resources:
[Crackmes.de]: A website that provides various crackme challenges for beginners and experts to practice their skills and learn new techniques.
[Reverse Engineering Stack Exchange]: A question and answer site for researchers and developers who explore the principles of a system through analysis of its structure, function, and operation.
[Tuts4You]: A website that provides tutorials, tools, papers, books, forums, and other resources related to reverse engineering.
[Open Security Training]: A website that provides free online courses on various topics related to security, including reverse engineering.
[r/ReverseEngineering]: A subreddit that discusses anything pertaining to reverse engineering.
We hope you enjoyed this article and learned something new. Happy cracking!
FAQs
What are the risks of using cracked software?
Using cracked software can expose you to various risks, such as:
Malware: Cracked software may contain malware, such as viruses, worms, trojans, ransomware, spyware, adware, etc., that can infect your device and compromise your data, privacy, security, and performance.
Legal issues: Cracking software is illegal in most countries and can result in fines or imprisonment if you are caught or reported. You may also face