It looks to me like they are changing the opcodes themselves. Not quite sure WHAT the changes are, as I have no idea what the original executable looks like, but I would guess that they are either changing some data values to improve things, or such.
Edit: And the reason they use XOR is that it's automatically reverting back to the original if you do it again: if we do 4 ^ 5, we end up with 1. 1 ^ 5 gives 4, so we're back to what we had to start with.
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Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
True, if you're trying to hack a simple game such as Windows pinball. Nowadays, hacking in general has become fairly sophisticated. It would behoove you to read Hoglund's book. Especially, chapter six.Originally Posted by RobotGymnast
To quote Hoglund:
Some game developers have gotten wise to the fact that hackers use disassemblers and debuggers to reverse engineer their games and have developed many countermeasures for use against them. These techniques include obfuscating program code and interlacing runtime checks to see if a debugger is present. Hackers can counter almost all of these tricks, but they must know about them first. This is a classic computer security arms race.
hmm.. interesting. I sort of meant this game in particular, but it's not really fun to hack anyway (hacking's more recreational for me.. I only do stuff without security, e.g. offline games).
Interesting-looking book though, thanks
