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+--- Thread: How to crack authentication using Ollydbg (/Thread-How-to-crack-authentication-using-Ollydbg)
How to crack authentication using Ollydbg - Mafia - 02-27-2016
Please note: This may not work for all programs, some may be more advanced than this, however this will work for the majority of programs.
Hello, today I am going to show you how to crack a simple authentication for a program, to do this you will require OllyDbg.
Okay, so first we will need a program to crack, for me I will chose a csgo external cheat, I purchased this one for $5 for a week's access.
1. First of all we will need to have a basic understanding of how the program works, to do this we can see what files are given to us:
Spoiler:
![[Image: 02b609de5f92924c00be1ae65306109d.png]](https://i.gyazo.com/02b609de5f92924c00be1ae65306109d.png)
In the config file we can see that a username and password is required (as expected) and aimbot settings, we want to enter some random information here so we can get the error message, as we can see here it is:
Spoiler:
![[Image: 05a28bc3a1df1a6de6d9c8c58189472a.png]](https://i.gyazo.com/05a28bc3a1df1a6de6d9c8c58189472a.png)
This is the message we are going to be looking for in Ollydbg.
2. Next it's time we opened our file with OllyDbg, you will see something like this:
Spoiler:
![[Image: fda1d4d09cf7614c4e722d1439837860.png]](https://i.gyazo.com/fda1d4d09cf7614c4e722d1439837860.png)
This is useless to us at the moment as we need to find where the program is loaded, luckily you can find this by just pressing the run button at the top, you will see something like: "CALL PROGRAMNAME.HEX" -> You then want to click on it and then right click and search for -> all referenced strings and you will see something like this:
Spoiler:
![[Image: ba397a7ca7cec04b4382c8a66c138fc0.png]](https://i.gyazo.com/ba397a7ca7cec04b4382c8a66c138fc0.png)
This is all the text in the program, now you want to double click on the text which you received when the login was wrong, this will take you to the call, the main thing we are looking at is the hex code on the left hand side which can be seen here:
Spoiler:
![[Image: 4f1273c11387168971162a3825cd8aec.png]](https://i.gyazo.com/4f1273c11387168971162a3825cd8aec.png)
This is a very important part, you need to remember the highlighted hex, that is the address of that call, please note: yours will be different from mine.
3. Now we need to search for this hex code, normally it will be a few lines above it, depending on the coder, it will most likely be called something like 'JE PROGRAMNAME.HEXADDRESS, the JE function jumps to an address if it is equal to zero, from this we can presume that there is a function which sets a boolean to true or false if login is correct (well duh). So now we need to reverse this so that the function is reversed and it displays it if it is correct.
Now we want to double click on the text to edit it and change it to 3 different things:
JZ -> Won't work for most will mean Jump if 0, most used if a button is not pressed.
JNZ -> Jump if not 0 -> most likely to work with most programs
JMP -> Jump regardless.
(Brief explanation anyway, if one doesn't work try another!)
4. After confirming the change you will see that the text is red, next you want to right click and goto Copy to executable -> All modifications and then hit copy all.
Spoiler:
![[Image: 66114728cda724a58335a9a281b29731.png]](https://i.gyazo.com/66114728cda724a58335a9a281b29731.png)
5. Then you want to right click anywhere and press save file. That's about it!
As I said this is a very rushed tutorial and I may have only touched the surface, however I believe that this will give you a brief understanding on how to crack a simple authentication. There are other ways to do this and some coders may counter measure this.
Enjoy
Mafia
RE: How to crack authentication using Ollydbg - Killpot - 02-27-2016
god this is shit kys
RE: How to crack authentication using Ollydbg - Mafia - 02-27-2016
(02-27-2016, 12:52 AM)Killpot Wrote: god this is shit kys
what a fag
RE: How to crack authentication using Ollydbg - tyzwut - 03-09-2016
I think what you are explaining only works in rather simple programs. It's usually much more difficult than this.