• Posted on February 18, 2013

Modifying Compiled C Programs in Hex Editors

If you ever wanted to make changes to a program and didn’t have the source code you are usually out of luck. But with decompilers you can turn the compiled exe, or other executable file into ASM (Assembly) or just edit the HEX code. If you are looking to make a lot of changes decompiling to ASM is suggested since you can more clearly understand what is happening. But if you just need to modify a few variables and strings, why not just open it up in a hex editor quickly? Keep in mind that when you do decompile a program, it’s going to be a lot harder to understand since the compiler optimizing the original code. If you have the option to, always edit the source code that is available.

Today David will create three different programs, and show you how to modify strings, integers, and how to put this to use in the real world. Of course using this on existing programs is usually not allowed by the EULA, so make sure you have the correct permissions to make these changes.