Well, a software (I.e. a. exe file) is a long list of numbers. Some are commands like “do something when the user clicks there”, some are data, like text on a button.
If you are very familiar with those intricacies, you can change a few bytes here or there to change what the program does.
No, there are tools like “hex editors” that allow to edit a file in a more controlled way. I don’t think opening a binary file in notepad would do anything good to that file…
This all is under the umbrella of reverse engineering or software cracking. This is an old e-magazine (https://www.exploit-db.com/ezines/kr5hou2zh4qtebqk.onion/ARTeam/ARTeam.Ezine.Number2.pdf) showing a rather easy way to add a menu to notepad (Windows XP/7/10) to add functionality. This is in chapter 1. In this case only small modifications are done in the original software (resources and loading a dll), but the changes could have been done without a dll library using code caves or a new section instead.
Reverse engineering is a very large area containing many topics, depending on the software, the methods, the hardware, and even the operating systems. So you need to learn a lot. It starts from crackmes, patching, debugging and reading assembler code. Then it goes to anti debugging techniques, manual unpacking of protections/packers, understanding protocols and file formats, keygenning, custom authentication servers, inline patching, copy protections (disc based and online) hypervisors and drivers and much much more.
Well, a software (I.e. a. exe file) is a long list of numbers. Some are commands like “do something when the user clicks there”, some are data, like text on a button.
If you are very familiar with those intricacies, you can change a few bytes here or there to change what the program does.
I’m more curious as to the process than the concept I guess. Open your exe in notepad, hold alt, and mash the numpad?
No, there are tools like “hex editors” that allow to edit a file in a more controlled way. I don’t think opening a binary file in notepad would do anything good to that file…
This all is under the umbrella of reverse engineering or software cracking. This is an old e-magazine (https://www.exploit-db.com/ezines/kr5hou2zh4qtebqk.onion/ARTeam/ARTeam.Ezine.Number2.pdf) showing a rather easy way to add a menu to notepad (Windows XP/7/10) to add functionality. This is in chapter 1. In this case only small modifications are done in the original software (resources and loading a dll), but the changes could have been done without a dll library using code caves or a new section instead.
Reverse engineering is a very large area containing many topics, depending on the software, the methods, the hardware, and even the operating systems. So you need to learn a lot. It starts from crackmes, patching, debugging and reading assembler code. Then it goes to anti debugging techniques, manual unpacking of protections/packers, understanding protocols and file formats, keygenning, custom authentication servers, inline patching, copy protections (disc based and online) hypervisors and drivers and much much more.
That’s for sharing, now im wondering why my highly relevant degree never bothered to discuss reverse engineering!