Game/Program Cracking

[ihsir]

What is actually done when games/programs are cracked?
Is cracking some form disassemblimg/decompiling?

Can simple .exe files like that generated by prog languages get 'cracked' to reveal the source code. And is there some way to make them uncrackable.

From other posts on this site i learnt that disassembling will give the assembly code not the source code. can it programmed not to be disassembled also?

[s0nIc]

Well, i do know that KeyGens were created with the help of cracking or disassembling the .exe file.. there is a tool called W32Dasm which disassemlbes any 32bit windows file.. and yeah the first window shows u the assembly code but if you double click on a certain area of the code, W32Dasm translates it in normal words so you would know what code you are looking at..

and some people use HIEW to edit the exe file.

I only read this on a tutorial called "How to crack trial version softwares" so they wont be trial versions anymore.. i just dont remember where i read it.

[cold_connection]

Usually, cracking applies for sharewares, especially time limited ones or others which need a special registration number. The cracker will usually dissassemble the program to bypass the lines of code that either take the time limit or ask for a key.
Also, a popular crack for games is a key generator. This will generate a key based on an algorithm used by the game.
Yet another one for games is a crack that allow you to play without the CD. However, since CD's are so cheap nowadays, it becomes close to useless.

[bpx]

basicly, cracking is just modifying a PE file until the restrcition doesnt function anymore.
IE. reversing jumps, NOP'ing calls (to a minor extent normaly).

Cracking involves a fairly deep knowledge of assembly (if your good). Althoggh alot of programs are full of shite protection and rely on some lame packer to do the work for them (namely asprotect, aspack etc).

keygenning in some respect is almost as easy, sometimes you can literly cut and paste the algo and paste it into your keygen template.

[bpx]

oh, i might add.


you will find 99.9% of modern day games are DEMO's. which means they lack the features of a full/shareware version. which means technicly they cant be cracked without playing a little reverseme with them. that means adding your own code to make it work....pointless for games

if you are interested in cracking i have written several large tutorials.

[dieterle81]

@bpx
if you have written an interesting tutorial please feel so free and publish it here.

cheers

[bpx]

ok. i am at work atm, but i do have one online atm. itmay be a little to advanced for you if you've never cracked anything before.

Manual Unpacking and Inline Patching A UPX Packed Target


that's one i did a fairly long time ago.



btw. incase you didnt notice the nick i use for cracking publicly is RaX

[dieterle81]

i've to learn more assembler :-))

cheers,

[ihsir]

wow, thanks for the info guys, esp you bpx.. thanks a lot. i'll check your tut.

[bpx]

np

I was trying to keep my real nick kind of a secret due to the increasinly large ammount of emails i receive ecery day.

If you want more tutorials then you can icq me or something.