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January 1999 |
"eWords v1.00" (Finding yet another compare) |
Win '95/'98 PROGRAM Win Code Reversing
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by Punisher |
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Cracking 4 Newbies |
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Program Details Program Name: ewsetup.exe Program Type: Scrabble type game Program Location: http://www.softseek.com/ Program Size: 1.06 MB |
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Tools Used: Soft-Ice -- Debugger |
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Rating |
Easy ( X ) Medium ( ) Hard ( ) Pro ( ) |
There is a crack, a crack in everything. That's how the light gets in. |
eWords v1.00
(Finding the repz cmpsb)
Written by Punisher
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Introduction |
The author says:
"The object of the game is to outscore you opponent(s) by building words on the grid of squares. Words are placed the same way as a crossword puzzle. You begin with a small collection of randomly-lettered tiles. "
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About this protection system |
Registration is via the Startup nagscreen or the Help/About Menu Item. You must enter :-
Registration Code:
The serial number is hard coded.
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THE ESSAY |
Install eWords and run it you are presented with a nagscreen. The nagscreen has an edit box to enter your registration code. Enter a fake registration code.
Go into soft-ice by pressing ctrl-d. Set a breakpoint on GetWindowTextA. Leave Soft-Ice by pressing ctrl-d.
>>> BPX GETWINDOWTEXTA
You are now in the nagscreen again click the OK button. Soft-Ice breaks in Kernel at GetWindowTextA. Press F11 to get back to the caller and you will be in eWords code. Now do a search for your fake regcode.
>>> S 0 lffffffff '45454545'
When Soft-Ice finds your fake regcode set a breakpoint on that range with read and write access.
>>> BPR 013f:0064234A 013f:0064234A+8 rw
After setting that breakpoint search again to see if the fake regcode is copied to other locations. Do this by type S and pressing enter.
If there are more instances of the fake regcode set breakpoints on these ranges.
Now let the program run by pressing F5. Soft-ICe will break a couple of times. Each time it breaks press F5 until it breaks at this instruction.
REPZ CMPSB
This is where it compares the fake regcode and the real regcode. To see these codes dump es:di and ds:si. you will see your fake regcode and the real regcode.
write down the real regcode. Let the program run and until you get the messagebox which tells you your registration failed. Now get Enter the real regcode and your game will be registered.
I will like to say thanks to +Fravia, Sandman, CrackZ, Cruehead, Iczelion and all the others out there who help by providing the knowledge to make this possible.