Cracking Projects For Newbies

Answers to questions Wednesday, 10-Feb-99 18:16:33 208.161.55.253 writes: Greetings Crackers, I will do my best to answer these questions. I was able to find the comp routine easy enough and even find the real reg number, but because my asm reading is not what it should be I had to read some other threads to to follow the program. Am getting better with SICE as these projects go on. Thanks to The Sandman! Question 1. Explain as best you can, what the above code fragment does. Comment all four lines. I'm looking for your comments that:- :0040B73A call 0040CCC0 <-- calls the compare routine :0040B73F add esp, 00000008 <-- I think this adds 8 to the value at esp? dont know why :0040B742 test eax, eax <-- test eax for 0 or FFFFFFF :0040B744 jne 0040B9BC <-- if not equal 0 then to bad cracker a. Show what values of importance are returned in the PC's internal registers after the CALL 0040CCC0 has been executed. b. What is the reason for the ADD ESP, 00000008 instruction? BTW, register ESP is a STACK Register. (Dont know. Does this adjust the stack?) c. The instruction TEST EAX,EAX is checking the eax register for two possible values, what are they and what do they signify? (0 or FFFFFFFF 0 = good reg number FFFFFFF = bad reg number d. Where does the instruction JNE 0040B9BC take us to? (Bad cracker msg) Question 2. Explain how this program compares our *fake* serial number against the *real* one. (hint, check the code between :0040CCC0 to :0040CCF9 ) (first the prog loads the fake reg number, then it loads the real reg number. Then it compares the first bite in the fake to the first bite in the real. If they do not match then ret with FFFFFFF and on to bad cracker msg. if they match then on to the next bite. I was able to change the two jne so I could run through the entire fake reg number without being kicked out. This allowed me to read the real number one digit at a time.) Question 3. Explain how our User Name: Pirate Copy is converted into a 16 character hex code. ( I need help on this one, but didnt have the time to follow princes explaination all the way through. I dont believe I would have found this on my own.) Will have to work on asm some more. Later Task 3

Message thread:

Dancer: Project 6 "The Games Begin" (03-Feb-99 22:49:04)

The Sandman: Re: Project 6 "The Games Begin" (06-Feb-99 17:51:21)

Dancer: Re:To The Sandman (07-Feb-99 15:26:27)

Re: Task 2 (07-Feb-99 16:19:09)

Re: Re: Task 2-Upon futher review (07-Feb-99 16:34:03)

Task 3: Answers to questions (10-Feb-99 18:16:33)

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