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- Tutorial Number 5
-
- Written by Etenal Bliss
- Email: Eternal_Bliss@hotmail.com
- Date written: 23rd Jan 1999
-
- Program Details:
- Name: CrackMe v4.0
- Author: Magenta
- Language: Visual Basic
-
- Tools Used:
- NuMega SmartCheck 6.01
-
- Cracking Method:
- Analyzing Data in SmartCheck
-
- Viewing Method:
- Use Notepad with Word Wrap switched on
- Screen Area set to 800 X 600 pixels (Optional)
-
- __________________________________________________________________________
-
-
- About this protection system
-
- No disabled function. Protection is based on a 8 digit combination which
- must satisfy an algorithm.
-
- __________________________________________________________________________
-
-
- The Essay
-
- As this is a tutorial for newbies, I'll go into details about how I go about
- cracking the program. I suggest that you read this tutorial first.
- When you have completed the tutorial, leave this tutorial open and follow
- the instructions while using SmartCheck. Re-do it once more after you have
- completed the step by step guide...
-
- __________________________________________________________________________
-
- Data Analysis in SmartCheck
-
-
- Run SmartCheck. Load the program using it by using "File", "Open"
- and choose Crackme#4.exe
-
- If this is your first time using SmartCheck, do the following:-
- Under Program Settings:-
- Error Detection: "tick" all boxes except "Report errors immediately".
- Advanced: "tick" first 4 boxes.
- Make sure "Suppress system API and OLE calls" is not "ticked".
- Reporting: All boxes "ticked" except for "Report MouseMove events
- from OCX controls"
-
- **I have captured the images of the three boxes for better reference. They are
- available on http://crackmes.cjb.net
-
- Run Crackme#4.exe in SmartCheck by pressing F5. Type in any registration
- code you want. (I used 26398457) Then click "Ok". You will get a
- "You failed, try again loser" message. Exit the program.
-
- Ok. You will see a few lines in the left window. Look for Command1_Click.
-
- **This is the subroutine in VB that is called when you click on the
- "Ok" button.
-
- Click on Command1_Click. Under "View" in SmartCheck, choose
- "Show All Events" and "Show Arguments".
-
- **This is also capture in a file called setting4.jpg file on
- http://crackmes.cjb.net
-
- **Make sure you click on Command1_Click first or you will be lost
- in a sea of codes!!!
-
- Click on the + sign next to Command1_Click to expand the threads
- under it. You can go through every single thread if you want.
- I'm saving you time now by telling you what to look for...
-
- Note: what I entered is 26398457
-
- Interesting lines include:
- 1) __vbaVarMul(VARIANT:String:"2", VARIANT:String:"6") ...
- **1st number multipied by 2nd = 12
-
- 2) __vbaVarAdd(VARIANT:String:"3", VARIANT:String:"9") ...
- **3rd number joined with 4th = 39 and not 12!!
-
- 3) __vbaVarSub(VARIANT:Double:12, VARIANT:String:"39") ...
- **Answer from step 1 subtracted by answer from step 2 = -27
-
- 4) __vbaVarMul(VARIANT:String:"8", VARIANT:String:"4") ...
- **5th number multiplied by 6th number = 32
-
- 5) __vbaVarAdd(VARIANT:Double:-27, VARIANT:Double:32) ...
- **Answer from step 3 plus answer from step 4 = 5
-
- 6) __vbaVarAdd(VARIANT:Double:5, VARIANT:String:"5") ...
- **Answer from step 5 plus 7th number = 10
-
- 7) __vbaVarSub(VARIANT:Double:10, VARIANT:String:"7") ...
- **Answer from step 6 subtracted by 7 = 3
-
- 3rd line from step 7 you will see
- 8) __vbaVarTstEq(VARIANT:Double:3, VARIANT:Const Integer:10)...
- **Answer from step 7 is compared to 10
-
-
- Overall formula for the protection scheme:
- ((a * b) - (c & d)) + (e * f) + g - h = 10
- where a = 1st number, b = 2nd number, c = 3rd number etc...
-
- So, by understanding this, we can create our own correct serial.
- For example, g = 1 and h = 1
- So, ((a * b) - (c & d)) + (e * f) = 10
-
- If (a * b) = 16, (c & d) = 12 and (e * f) = 6, we will get 10
- So, a = 2, b = 8, --> 2 * 8 = 16
- c = 1, d = 2, --> 1 & 2 = 12
- e = 2, f = 3, --> 2 * 3 = 6
- So, (16 - 12) + 6 = 10
-
- One of the correct serial will be 28122311
-
- __________________________________________________________________________
-
-
- Final Notes
-
- This tutorial is dedicated to all the newbies like me. I've tried to
- explain everything in details.
-
- And because I'm a newbie myself, I may have explained certain things wrongly
- So, if that is the case, please forgive me.
-
-
- My thanks and gratitude goes to:-
-
- The Sandman
- All the writers of Cracks tutorials