Introduction to the world of cracking
A beginners tutorial written by ceobadman
Intro:
What is cracking?
Cracking is how i like to say a art a xpression.Everyone can handle it.But not everyone can do the best of it.If you like to crack you`ll see that it isnt easy to understand at first but after recieving some experience and knowledge it is incredible.If you have learned the real cracking you arent only a cracker.You are more then a cracker.With the art of cracking you`ll gain more knowledge about your PC the programms you running on it and how they work.You`ll understand how a programm works and how to manipulate it that it can be usefull for you.And it dont mean that it`s illegal.
Offcourse it`s not 100% legal but it can be usefull for you in your later life.You have experience about the ASM-Code understand the function of programms and other applications and maybe it bring you up to a programmer?Who knows.But at first you`ve to learn it step by step.I`ll help you with my tutorials and i hope you understand the way how i explain it.Excuse my english i know its not the best but i`ll do my best.
Step one:
What do we need to crack?May i need some knowledge about assembler or anything else?
No.I made this tutorial for all the beginners in the net who dont understand anything about
ASM-Code or the internal function of applications.Like you and everyone else i also started with cracking some time ago.And it tooks much of my life time to what i know today about cracking.
I think there are many tutorials which are good and i dont wanna say anything against them.
But i think the most tutorials are quick written memory killer with which you cant do anything.
I always had the problem that i dont understand what they mean.Like what is a nop or what mean the je,eax,jump signs.What they mean with jump to badboy and replace the jump if not equal with the jump if equal command.All these things and many more makes me sometimes worry about what i want to learn.I thought that i`ll gave up and forget the thing with cracking.But everytime if i do that some time later i cant and have to learn the way of cracking.Yes sometimes you`ll think oh man what do you mean it doesnt work!But dont give up.Everyone passed this point of time and you`re not the first and will not be the last one.You have to learn again and again.And then at any time you`ll see that it was good what you`re doing all the time and you`ll be proud about it.
The software we`ll need:
At first the only thing we`ll need is W32Dasm8.9 (a Windows disassembler) and HIEW (its a good Hex-Editor i think it`ll be the best for you at first).Thats all.In the following tutorials (i hope there`ll be any of me) i`ll explain how to work with soft-ice and how to handle the asm-code.But at first you need as a beginning cracker only the two things.
Some knowledge at first:
As you know its not very easy to handle all the asm-codes and i think you dont know much about them.So i`ll explain the most needed commands.
There we have to know that every two numbers in asm-code are representing one byte.
Like the number 75564345 = 4bytes.The 75 is one byte the 56 is one byte the 43 is one and the 45 is one byte.So we have 4 bytes leading the command at this point.If we want to replace them later we now know that we have to replace always two numbers with two other numbers.Like the 75 (in hexadezimal it stand for jne.Jne means jump if not equal) we can change to 74 (in hexadezimal it stand for je.Je means jump if equal).This in most of times is enough to crack a game or to register a programm so it`ll not say "sorry invalid password" or something else (please dont think its so easy i take it as a very simply protection).Cause if we change the value of 75 (jump if not equal [means that the application is checking something like if there is a cd present in drive or is it the same password like saved in the programm and if it isnt right like there is no cd in drive or the password you entered is not valid it will jump to "BadBoy" and the programm pop up you the error message] by the way "BadBoy" is in cracker language something like the one dude who call the error message)
to 74 (jump if equal so the programm think there is a cd in drive or the password is valid and will jump to "GoodBoy".GoodBoy is the one who makes the way clear).You`ve to manipulate the application so it think there is a cd present or password is valid and it continious with the programm.Remember that the exe runs up to down.So the commands which call the error messages are placed before the error messages.The only thing i mean is that if you found the error message (i`ll explain later how to do it) you have always look up in the asm-code not down.Its like you.If you read a book or a text you start on line one and read your way down.The programm do the same.It checks from line one of the asm-code to the end of the code if there is all correct.And if it found at line 9 a error it jumps down to the "BadBoy".It cant jumps up cause there he checked everything and there arent complications.So if you found the error message look up (before it) and you`ll find the command which call the error message on the screen.Ok now some things about the numbers and things you`ll see if you disassemble a exe (here are only the needfullest things you`ve to know at this point of time):
je (hexadezimal is 74) = Jump if equal
jne (hexadezimal is 75) = Jump if not equal
nop (hexadezimal is 90) = No operation
call (no random hexadezimal) = call a operation
jmp (no random hexadezimal) = jump to string/operation
This are the five basics we`ll need at first.The other i`ll explain in later tutorials when you gain more experience in asm-code.
Ok now we`ll take a look what does they do in a asm-code string.
Je (Jump if equal) jumps to a operation if he found what he check.
Example:
The game need a cd to start the main game.So the "jump if equal" je command check if there is a cd in drive.If there is a cd in drive he`ll continous and give a information away to the commands after him.Thats a equal operation.The cd was found (equal) and it continous in asm-code (jump if equal).
Jne (Jump if not equal) jumps to a operation (most times BadBoys that mean,to the error message you`ll recieve on your screen) if he dont found what he check.
Example:
The game need a cd to start the main game.So the "jump if not equal"jne command check if there is a cd present in drive.If not he`ll jump to a "BadBoy" and you`ll recieve the error message on screen like "Cannot find CD in drive.Please insert CD and click on OK."
Thats a "jump if not equal"operation.The check failed (cause he dont find a CD in drive) and he jump to the "BadBoy" and the "BadBoy" end the load process and let the error message be shown on your screen.
Nop (no operation) a nop command kill the current operation like checking after CD in drive or checking if password valid.
Example:
The game need a cd to start the main game.Its like before cause you set the nop command.
You can replace the jne/je/call/jmp commands with a nop command.The nop will then disable the jne/je/call/jmp command this mean that the programm dont check if a cd is present in drive and continous in asm-code.The game run (you can do that but its also a style for simply cd protections).
Call (Call a operation) a call command do what his name say.He call a command what can be a error message,a nag screen...This you can disable with a nop command.
Example:
I dont know what i can say more.
Jmp (Jump to a string/operation) a jmp command is like a call (not the same but...you can say it is) he dont call commands but jump to them.
Example:
The jmp jumps to a string/operation which will call a error message or to a BadBoy...The jmp
you can also disable with a nop command.
I think thats all you`ve to know for now about the commands in asm-code.In this tutorial we`ll handle only with these few commands.Thats enough for you at first to crack simply protections (no matter if cd or password).
About protection shemes:
There are enough protection styles you`ve to learn about and to learn how to disable them.
We have "normal" cd protections (a game is looking if there is a cd present if not it`ll not start the game),password protections (you`ve to enter a valid password [most times you find them in trial versions] if you dont enter a valid password you cant register or start the application),
time locks (most times in trial versions.You have some time to test a programm like three weeks and after the time it wont start/show a error message/you`ve to enter a password to unlock it),and in unusually times you`ve to get a unlock software from the programmer (the programm wont work without the +software of the distruber.This kind of protection is hard to find).Thats are the most usual protection shemes you`ll find on your way to a real cracker.
The easyest protections for us to crack are windows error message boxes (i think so).
Its a windows message box which will be shown on your screen with any text if you havent got a cd present or a valid password.This kind of protections you can see in EA applications like NFS/Fifa Soccer/NHL....Its very easy to crack cause the only thing you`ve to do is to kill the window (most times with a nop command or change je to jne /jne to je).Also we can find this kind of protections at password locked applications.If you enter a invalid password you`ll recieve a windows message box too which include a text like "invalid password" or something else.Then we`ve ingame error messages which are harder to crack.Cause W32Dasm show you only the windows box messages and not the ingame messages.For this kind of protection we need soft-ice debugger (i`ll explain in later tutorials how to use soft-ice).This kind of protection you can see in games like Commandos/Grand TheftAuto/Descent Freespace.And the timelock protections can be shown to you as a windows box and as a "ingame" error message(i`ll call them NAG screens).Those kind of protection you can see in Paint Shop Pro.
In this tutorial i`ll show you how to disable the windows message boxes with W32Dasm version 8.9 and with Hiew.We`ll crack WinRAR and WinRAR95 (may be a game too like Anno1602 or anything else i dont know how much time i`ll get and if the tutorial wont be too long).
Beginning with cracking:
Now lets start with the main thing you want to learn.Cracking.I`ll show you now how to handle the basic commands of W32Dasm89 and Hiew.We`ll crack now WinRAR95.exe (we`ll make a full registered version of the trial).At first we start the programm.We`re in.
What can we see?At first we can see on top of the window "WinRAR (unregistered version)"
Thats very good for us cause the "unregistered version" status behind the "WinRAR" tell us
that it is unregistered and that it`ll be not shown if it registered.Now we click on "Options"
and then on "Register".Now you can see a windows box (these kind of boxes i mean which are easy to crack for us).Now enter in the text boxes what you want like as a name "Test" and as a number "12345" and click on ok.You`ll hear a sound and another windows box pops up which tell you "Registration Failed".Thats all we want to know.Close WinRAR95 and go to your Ms-Dos box.Now in Norton Commander (you can use windows commander too) make from your WinRAR95.exe two copies.One of them named WinRAR95.w32 (for W32Dasm89) and one named WinRAR95.exx (a saved copy if you change wrong bytes).
Now i`ll exlpain why we do these copies.Its very easy.If you disassemble a exe like WinRAR95 and you`re working in W32Dasm89 you cant run the WinRAR95.exe as the same time in Hiew or in Windows Explorer.You make a second copy named WinRAR95.w32 (you can call it like you want no matter but its good that you see its for W32Dasm89).This copy you`ll disassemble with W32Dasm89 and you can everytime start the original exe in Windows or change the bytes in Hiew.The second copy WinRAR95.exx is only a save recovery copy.If you change wrong bytes in Hiew or anything else so that it wont run you can rename the WinRAR95.exe with WinRAR95.exx.And try it again (remember its always "try and error" technique).Ok if you make the two copies start W32Dasm89.Now click on the first button on the top (or click on Disassembler and then on "Open file to disassemble".A window pops up and you can chose the file you want to be disassembled.
Change your directory to your WinRAR directory and click on WinRAR95.w32.
Now W32Dasm starting the disassembling process (if you have low system memory or low HD memory it`ll take some time).You can always click on the button in the midle of the screen called "Cancel Disassembly" which will abort the disassembling process.If the exe is disassembled it may be that you see no "normal" signs but WinDings written lines.
Dont worry you can change your font.Click on "Disassembler" then on "Font" and at least on "Select Font".Now you can chose the font you`ll use in W32Dasm89.I think the best one is Arial.Change the font.Now you have your selected font present in W32Dasm89.Click a second time on "Disassembler" "Font" and then on "Save default Font" (if you dont do that at your next disassembling file you`ve to change the font a second time).Now you see the asm-code.It will not tell you much cause you dont know what all the commands mean.Now click on the button next to the "Print" button called "Strn Ref" (String Data References).A window pops up.Now you can see all the error messages you can recieve from the exe.Do you remember what does WinRAR said if you entered the wrong code?It said "Registration Failed".Now look at the text and search for the message.Got it?Double click on it.In W32Dasm you`ll be warped to the position in the asm-code where it let pops up the error message you`ll recieve on your screen when you entered the wrong code.
If you make it right you`ve to look at a screen like this:
:00413A8F 6A6A push 0000006A
:00413A91 E863640000 call 00419EF9
:00413A96 59 pop ecx
:00413A97 50 push eax
:00413A98 FF7508 push [ebp+08]
* R e f e r e n c e T o : U S E R 3 2 . M e s s a g e B o x A , O r d : 0 0 0 0 h
|
:00413A9B E8120B0100 Call 004245B2
:00413AA0 33C0 xor eax, eax
:00413AA2 A358674200 mov dword ptr [00425758], eax
:00413AA7 A338564200 mov dword ptr [00425638], eax
:00413AAC A34C564200 mov dword ptr [0042564C], eax
:00413AB1 EB56 jmp 00413B09
* Referenced by a (U)nconditional or (C)onditional Jump at Adress: <---------This is our one
|:00413A82(C)
|
* P o s s i b l e S t r i n g D a t a R e f f r o m D a t a O b j - > " Wi n R A R "
:00413AB3 68D86A4200 push 00426AD8
:00413AB8 FF359C644200 push dword ptr [0042649C]
* R e f e r e n c e T o : U S E R 3 2 . S e t Wi n d o wT e x t A , O r d : 0 0 0 0 h
:00413ABE E86B0A0100 Call 0042452E
* P o s s i b l e R e f e r e n c e t o S t r i n g R e s o u r c e I D = 0 0 0 4 8 : " n o r m a l "
:00413AC3 6A30 push 00000030
* P o s s i b l e R e f e r e n c e t o D i a l o g : A R C I N F O D L G , C O N T R O L _ I D : 0 0 6 C , " "
This asm-code you`ve to see on your screen if you doubleclick on "Registration Failed".
Now you can remember what i said some lines before.The asm runs from top to bottem (i like call it T2B hehe).That means that the jne/je we have to change is anywhere up.But who
we know which it is?Now we can try to change everyone we see (like try and error) or we use the "Goto CD Loc" (Goto code location) button on the top.We click on it and a little window pop up.On bottem right of the window is a text box "Code Offset (Hex)".Now we take a look on the asm-code.We can see the line "* Referenced by a (U)nconditional or
(C)onditional Jump At Adress:" then the line next where is the adress we have to know
"|:00413A82 (C)".Thats the number we have to enter in the code location window its 00413A82.At this adress we`ll find the jump which will send us every time to the error message if we enter the wrong code.Click on ok in the code location window.
Now you are anywhere up in the asm-code.The Bar is on the line which let us jump to the message.Its a jne (jump if not equal).The Bar changed his color to green (he`ll do that only at jump/calls.Now look down on the bottem of the screen.There is a line which looks like:
Line:34985 Pg 467 of 998 Code Data @:00413A82 @Offset00013082h in File:Winrar95.w32
The only thing what we`ve to remember is the number after the @Offset.Its 00013082 (the Bar have to be on the jne).Write it down (you dont have to remember all the 000 its enough when you remember only 13082.Ok now go to HIEW (you dont have to close W32Dasm).Its no matter which kind of exe you start (if H.exe or H95.exe).In HIEW (its like Norton Commander) you can trace through the directorys.Go to your WinRAR directory and click on your WinRAR95.exe.Hmm dont know what that is huh?Click on F4 (select mode window) and then chose "decode".The screen change.You can now see all the jne/je/eax..commands
and have to click on F5.On the top left corner you can now enter the @Offset number (you wrote it down a few seconds before).Here its no matter if you type the 000 or if you type only 13082.Type 13082.You are at the jne command.Now click on F3 (edit).Now you`re able to change the value.Change it from 75(jne) to 74(je) and click on F9(update).Then click on F10.
You have changed the value of jne.Now you can test if it work.Click on your WinRAR95.exe.
The programm start.Now do the same like before.Go to registration and enter any name and code.Click on ok.What happens?No more error messages?A pop up window display that your registration was successfull.The message on the top next to WinRAR was killed (Unregistered Version) and you`re fully registered.Ok.That was the one way.But there is a second.Also we can kill the Unregistered status on the top of the window.We`ll do that now.
Load your uncracked save copy of WinRAR95.If you start it you can see on the top a message which tells you that its a (unregistered version).Go to W32Dasm and load your WinRAR95.w32 file.Now click on String Data References Button.Look for "(unregistered version)" (it have to be exatly (unregistered version) cause there are two of them!).Do you found it?Doubleclick on it.You was warped to the point where is it.Its like before.You have to do the same thing like before.You see the "*Referenced by a (U)nconditional or (C)onditional Jump At Adress:" line?Click on "Goto code location"button and enter the number.Its
00418AAA and click on ok.You was warped to the point which let the asm-code jump to the message if it is not registered.Its also a jne (jump if not equal) command.Write down the @Offset number its 000180AA (you can leave the 000 alone).Go to HIEW, load your WinRAR95.exe, click on F4 (decode), then on F5 (goto), enter 180AA and click on enter.
You`re at the jne command.Change the value of jne to je (75 to 74) save it and leave HIEW.
Remember that if you want to manipulate a exe like WinRAR you have to close winRAR on Windows desktop or you`ll recieve a message like "error only read mode".Now if you changed the value you can test if it works.Start your WinRAR95.exe and you see that the message is no more.We killed it.Now you have no message on the top and you can enter any name and code and it`ll unlock WinRAR95.The same way you`ve to do on normal WinRAR.Everytime if you want to crack a simply protection you can use this way.Change jne/je to je/jne.Or to nop it.
Remember the basics:
You have to remember the basics.If you want to crack a game or a application start it and look which kind of error message you recieve.If it is a Windows Message Box you can crack it with W32Dasm.If it is a ingame error message you`ll better crack it with soft-ice debugger.
Remember the error message and make to recovery files of the start.exe.One called *.exx (if you nop or manipulate anything wrong so it wont run or have any errors you can rename it with the original exx file) and one called *.w32 (this file is for W32Dasm you have to use it for disassembling it with Wdasm).Then go to W32Dasm and disassemble the w32 file of your start.exe.If it is disassembled click on String Data References button and look out for the error message (you can also click on search and enter your keyword like sorry or unable...)
you recieved on the screen.If you find it doubleclick on it.On the asm-code enter the *Referenced by a (U)nconditional or (C)onditional Jump At Adress: number in the Goto code location window.Once you was warped to the location write down the @Offset number (you can leave the 000).Start HIEW and load the exe.Click on F4 goto decode.Click on F5 enter the @Offset number (no matter if you do that with the 000 or without them).If you was warped to the place where is hidden the jne/je/jmp/nop you can change the jne to je or the je to jne or you can nop a jmp/call (you can also nop a je/jne command but before you do that try if it run with changing the value).Save it and leave HIEW.Start your programm and see if it works.If not you make something wrong.Try to nop or change other values.If there is no Referenced by a (U)nconditional or (C)onditional Jump At Adress: number you have to trace some lines up and look out for call/jmp/jne/je commands you can nop or change.
How to nop:
Now i`ll explain how to nop commands.Nop stand for "No Operation".If you get any call/jne/jmp/je command you can nop it.The rules for nop are:every two numbers are one byte.That means if we have a number like E8992344 we have there 4bytes which wanna be changed.E8 is one byte 99 is one byte 23 is one byte and 44 is one byte.Replace the number with 90909090.If you do that in HIEW dont be worry when you enter the first 90 that it flips one line down.Enter three 90 again and save it.Also you can nop a 7456 (je) with 9090
or a 7589 (jne) with 9090.No matter if it is a jne/je/jmp/call.Sometimes you`ll see je/jne commands in numbers like F5848976 (i dont know if it is the correct command but i want to show you what to do if you see anytime a long je/jne command like this) at this point you can change only the 84 after F5 (84 is like 74 = je) to 85 and otherwise (85 to 84).What i`ll say is that you dont have to nop it.Most times you have to nop call commands.Or jmp (jump)
commands.
No comments:
Post a Comment