home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Hacks & Cracks
/
Hacks_and_Cracks.iso
/
hackersclub
/
km
/
library
/
cracking
/
xoanon-timelock.txt
< prev
Wrap
Text File
|
1998-03-25
|
8KB
|
181 lines
TimeLOCK DLL "a cracking approach"
The DLL i will talk about is a DLL frequently used to protect
commercial programs distributed on the web. This DLL provide a time
limit protection: after xx days your program will not run anymore
without purchasing.
The protection scheme is quite simple:
1) You are given a serial number by the program itself
2) You are asked to enter an unlock code calculated from this #
3) Name,Company and other stuffs doesn't interest the protection
Here the interresting findings:
1) Everytime the program is installed the serial provided changes.
2) The registering information are stored in the W95 Registry AND in a
file .TSF stored in some locations of your HD, in encrypted form.
For example, in GeoBoy v1.3.1 (one of the many programs protected with
TimeLOCK) if you search the registry for the word "GeoBoy" you will
find some locations where there are a bunch of strange characters....
that's your information, encrypted.
But in this approach we will crack the DLL brutally, so we will not
care much about the registry! Finally, if you want to reinstall it
after the trial is expired (eh eh.... are you too lazy to try cracking
it??? :) you have to COMPLETELY clean up the registry (all branches
where the word "Geoboy" dwells).
Now some Frequently Asked Questions:
Q: So, WHICH programs use this DLL? Where can I find them?
A: Well, i found a lot of programs that do use this DLL .... for
example: E-BroadCaster, NetObject Fusion v2.0, GeoBoy v1.3.1. They're
all on the web, search them using AltaVista or some other engine.
Simply put in the name of the program you are looking for, and then
get it!
Q: Ok dude, i found that program! how can i see if it's protected with
the DLL ?
A: Obvious..... it has to load it from your HD everytime it runs...
so, simply search it with a DIR /S (will dwell most of the time inside
the installation directory of your new program, or else inside
WIN/SYSTEM)
Ok boyz, now let's go cracking!
In this approach i will use as example target the program GeoBoy
v1.3.1. Find it on the web, it's done by NDG Software so i think
you'll easily find it (every software house has at least an
homepage!).
Well, fire your SoftICE as usually, light your cigarette (like me, or
if you prefer the +ORC way, prepare a good Martini Vodka!) and install
GeoBoy. Installed? Ok, now run it! You will see the classic TimeLOCK
window (it's the same in all the programs protected with it, this
makes it easy to see if a program use this protection scheme). Enter a
name, a company and an unlock code. As you can see, you have in the
window 3 edit lines.
Now enter in SoftICE and act as usual with password-protected
programs:
:TASK
hmmmm is GeoBoy its task name? ...... found! Let's do an HWND on it!
:HWND GEOBOY
good! let's see... we're searching for some edit boxes.... found!
Handle hQueue SZ QOwner Class Name Window Procedure
....... .... .. ...... .... .............
052C(2) 0D57 32 GEOBOY Edit 177F:00000BF4 *
0508(2) 0D57 32 GEOBOY Edit 177F:00000BF4 *
050C(2) 0D57 32 GEOBOY Static 178f:000052FA
0510(2) 0D57 32 GEOBOY Edit 177f:00000BF4 *
....... .... .. ...... .... .............
We found 3 edit references.... let's try BMSGging the first (but will
work alsoBMSGging on the others)
:BMSG 052C WM_GETTEXT
Break due to BMSG 052C WM_GETTEXT !!! SoftICE pops up again!!! Well,
now you are inside Windows95 Kernel (if i remember well) ... First,
disable the breakpoint with BD 00 (or it will break on anyother
GETWINDOWTEXT function.... generally if you found an entry point you
should disable the BP after...).
Now step some instructions (not too many) until you reach TL32V20. We
have reached the DLL, now you have to show all your cracking
capabilities! Well.... step step step and step, watching the
EAX,ECX,EDI,ESI after every CALL or MOV EAX or MOV ECX or LEA EAX or
LEA ECX (with D ). You'll soon find that the DLL use these register to
store the addresses to everything you enter (name,company,unlock code)
and also for the serial number (generated at every install) and the
correct unlock code.
You will also notice that the unlock code (es. 121212) you entered is
stored at EBP-14, while the correct one is stored at EBP-28.
Can we crack our target faking the MOV and LEA to these register? YES!
Watch this piece of code (you will reach it after some stepping once
you are working inside the DLL):
......
LEA EAX, [EBP-28]
PUSH EAX
CALL 10001D08 < Generate the correct unlock code for the
ADD ESP,04 serial you're provided with
LEA EAX,[EBP-14] < do "D [EBP-14]" and you'll see the code you entered
LEA ECX,[EBP-28] < do "D [EBP-28]" and you'll see the CORRECT code
PUSH EAX < save the location
PUSH ECX < save the location
......
Well..... we found something interesting, don't you think? Try
immediately to change the LEA EAX,[EBP-14] in LEA EAX,[EBP-28]. In
this way, the correct code is moved in EAX instead of the bogus code
that we have entered. Act as usual (write down some bytes after and
some before these LEA, write down also the bytes of the changed
instructions, search them with your hex-editor inside TL32V20.DLL and
patch it). To make your life easy, write down and use as search string
a LOT of bytes before the LEA instruction, or you will find a lot of
occurences of the same sequence inside the file.
Ok, patched? Well, now try it and look if it works! Load back GeoBoy
and enter whatever you want as unlock code. Wow! it seems to work! it
says "Thanks for purchasing!" Eh eh.... Xoanon rulez!! :) Now you
think that your program is completely registered. But...... But? Try
to load it another time...... AAARGH!!!! The time-limit reminder pops
up again! Why?
Well, it seems there are some other instructions referring to the code
you entered... Ok! Fire SoftICE again and back to work! Reach again
the point where you found the LEA EAX,[EBP-14] (now changed in
[EBP-28]). Step a little ahead and...... eh eh... look at this (some
instructions after):
..........
ADD ESP,08
TEST EAX,EAX < checks if the values at [EAX] and [ECX] are the same....
now they are, 'coz we patched the DLL before.
JNZ 10004028 < if EAX isn't 0 (bad unlock code) will jump. Now no, 'coz
EAX is 0.
LEA EAX,[EBP-14] < Eh eh.... this is the instruction we are searching for!
As you see with "D EAX", it will move again in EAX the
code you entered (which is a bad code, obviously)....
Probably we need to change it too? YEAH!!!
PUSH EAX < Saves the location
..........
This is the end. Act as you did before, changing this occurrence of
LEA EAX,[EBP-14] in a LEA EAX,[EBP-28], in order to move again inside
EAX the correct code), then search and replace these bytes in
TL32V20.DLL.
Try again to run the program..... it WORKS!!!!!!!!
To be really sure, do the following:
1) Save your patched *.dll
2) clean from the registry all the entries which refer to GeoBoy
3) delete the file .TSF inside the GeoBoy directory and
4) reinstall the whole program anew
Now simply copy your patched DLL over the original one and run GeoBoy.
Enter whatever you want, it says "Ok,registered"... Exit, run again
and again and again for ever... you won't see anymore the timelimit
screen!
Done by Xoanon/PiNNACLE in May 1997