Reverse engineer software code

But before exploring a binary, we need to determine its type with a hex editor. In our example, we use WinHex. The MZ signature at the zero offset corresponds to PE format files executables or shared libraries , so this is an exe file or dll. Most file formats have unique signatures. Instead, we'll dump its memory and try to run it. To do that, we open the packed executable file in IDA Pro. This time, we need to find the original entry point OEP into the application rather than the entry point of the packer.

The pusha command saves general-purpose registers to the stack. In the end, there should be the popa command which pushes the stored register values. After the popa command, there is a jmp to the original point of entry. Below the popa command, there is jmp 40A, which will eventually move to the original entry point. Now, we can try to follow jmp. However, IDA Pro displays another warning message:. In the process list, choose our application and put the OEP address into the field.

As a result, Scylla will show that the import table has been found. If we run our application now, it will crash, so we need to remove the relocation table. Next, we need to check whether the ImageBase is the same that the application loaded into memory.

When applied properly, reverse engineering can help you strengthen the security and improve the performance of your solution. However, quality reverse engineering is impossible without using the right set of tools and techniques. In this article, we covered some of the best reverse engineering software that our team of professional reversers uses when researching software. Most of these tools can only be used for solving specific tasks, but when combined, they provide you with all the capabilities necessary for extensive software analysis.

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Related services Professional Reverse Engineering[a]. Screenshot 1. IDA Pro interface. Screenshot 2. CFF Explorer interface. Screenshot 3. Screenshot 4. WinHex interface. Screenshot 5. Hiew interface.

Screenshot 6. Fiddler interface. Screenshot 8. Relocation Section Editor interface. Screenshot 9. PEiD interface. Screenshot Error message displayed by IDA Pro.

Application analysis results in IDA Pro. Test application's import table. Application info displayed in PEiD. Configuring the scanning process in PEiD. The result of application scanning with PEiD. Unpacking the application in CFF Explorer. IDA Pro analysis results for the unpacked application. The import table of the unpacked application. Debugger detection message. The NtQueryInformationProcess function.

Analysis of the NtQueryInformationProcess function. View of the test application in Hiew. Setting the code address in Hiew. The part of the code where the application crashes. Setting the relative address in jmp. Configuring IDA Pro to show commands in byte representation. Application values displayed in Relocation Section Editor. The value for adding MessageBox delta. MessageBox function calls. Function breakpoint options in API Monitor.

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