I've reverse engineering little game on windows 32bit.
I found a string in executable which was interesting for me (it is a board game and this string represents the fact that somebody made a move on the board).
You can see that in the string is moved into
eax. But more interesting part here is instruction before that
ebx will contain the coordinate of a move which player made. This is what I'm interested about. I want to dump this coordinate into a file. So what I want to do is to modify assembly(in my case this code is in dll) and just write that data(which is in
ebx) into a file.
I've done a little research but could not found anything useful. All I found is how to patch an executable like make a slightest modifications into assembly which is pretty simple. I was even wondering if there is any tool that could help me achieve this(like shift assembly code to make enough space for me to write some code in it).
One idea that I have is to write a shellcode which dumps data, then add that shellcode at the end of some section, find my string into .txt section, edit the code to jump to my shellcode and then back to original state. But that would be pretty hard because I'm not really experienced in writing shellcode.