Reverse Engineering RET Homepage RET Members Reverse Engineering Projects Reverse Engineering Papers Reversing Challenges Reverser Tools RET Re-Search Engine Reverse Engineering Forum Reverse Engineering Links

Go Back   Reverse Engineering Team Board > Reverse Engineering Board > .NET Reverse Engineering
FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 01-02-2009, 07:29 AM
.netter .netter is offline
Member
 
Join Date: Jan 2009
Posts: 19
Question .NET reverse engineering - how to start?

Hi,

I want to crack an .exe file which proff if there is a usb dongle plugged in. It's written in .NET and I used .Net Reflector for getting the source code.

This seems to be the cechk-function.

Do anyone have an idea how to crack the .exe-file. The -net reflectr code is not compileable

PHP Code:
private bool CheckDongleDialog()
        {
         ..........
        } 
I think it's no problem to change the function.

while (1=1) or something like that ...

But how should I start this problem-solving?

Last edited by .netter : 01-03-2009 at 05:02 PM.
Reply With Quote
  #2  
Old 01-02-2009, 05:47 PM
.netter .netter is offline
Member
 
Join Date: Jan 2009
Posts: 19
Default

nobody who could help me?
Reply With Quote
  #3  
Old 01-03-2009, 08:26 AM
pvlog pvlog is offline
Member
 
Join Date: Dec 2008
Posts: 6
Default

Hi,

If the reflector code doesn't compile, it's probably easier to use ildasm/ilasm.
Unassemble your exe with ildasm
locate the function private boolean CheckDongleDialog
replace its code by :
ldc.i4.1
ret

assemble with ilasm.
Regards,
Phil.
Reply With Quote
  #4  
Old 01-03-2009, 01:15 PM
.netter .netter is offline
Member
 
Join Date: Jan 2009
Posts: 19
Default

ok, thanks very much. I will try it today night.

cooool, it worked! Dongle function is inactive now! :-)

was not really hard (disassembling is nice!)

Last edited by .netter : 01-03-2009 at 07:44 PM.
Reply With Quote
  #5  
Old 01-04-2009, 04:43 PM
.netter .netter is offline
Member
 
Join Date: Jan 2009
Posts: 19
Default

Is there any tool available which tells me with which the .exe-file was compiled / in which language the source code was written?
Reply With Quote
  #6  
Old 01-09-2009, 05:12 PM
.netter .netter is offline
Member
 
Join Date: Jan 2009
Posts: 19
Default

Hi

I have one more question.

The disassembling with ildasm and reassembling with ilasm works but I tried to recompile the code I have disassembled without any changes but it's not a 100% working compile.

When I execute the original .exe-file it exists normally but when I execute my recompiled source I get a window with debug info (sending data to Microsoft). So it's not really a 100% compile.

Is there a better software than ildasm/ilasm available for .NET files?
Also it seems that ildasm doesn't disassemble 1:1!?
Reply With Quote
  #7  
Old 01-10-2009, 12:34 PM
.netter .netter is offline
Member
 
Join Date: Jan 2009
Posts: 19
Default

shit shit!

my own compiled appz has an error when uploading the firmware. It seems that here the ildasm disassembled other code than the original was. There is any problem with the Buffer when the firmware file will be send into the serial device.

Is there any other way for .NET .exe-files to disassemble and recompiling?
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump





Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.