anyone interested in cracking crackme's?

[mark_boyle2002]

Next, this is a public forum

Yes. Its also a community forum so if you don't intend to play nice with the guys your gonna find yourself being the lonely fat kid in the corner then banned.

[lepricaun]

Nice!

the 6th one is available now.. this WILL require some ASM skills...

[sec_ware]

this WILL require some ASM skills...

Indeed, it did Again, well done.

Instead of solving crossword puzzles while using public transportation,
I am now checking asm code - back to the old times

Lepricaun, waiting for the 7th!

[phishphreek]

lepricaun: Nice little exercises. Might I suggest a solutions page? I realize that there are many different ways to solve your challenges... but a general solution for those not too familiar? I tried the first few and found them pretty easy using a hex editor or even notepad.

I'm not a programmer by any means (I know the basics of C/C++, etc.) and will surely find them a nice challenge as I progress. However, if I am unable to complete the challenge, I would be interested in relevant reading material. Don't give me the answers, just point me in the right direction. I'm learning a bit of Intel ASM in one of my "hybrid" classes now, but we are not that far... focusing on hardware and computer org. more than programming ASM. More ASM to come later in the semester.

[;TT]

Originally posted here by sec_ware
Indeed, it did Again, well done.

Instead of solving crossword puzzles while using public transportation,
I am now checking asm code - back to the old times

Lepricaun, waiting for the 7th!

I'll swallow my pride... I got up to 4 and dropped out dead like a fish. I'm guessing decompiling the code is necessary so how about posting your answers for I am curious now.

[edit]

BTW,

if this is addressed to me, yes i'm not a native american or englishman. but i think i'm doing pretty well for a foreigner

That edit refers to the reason my post has an edit time... I had a spelling issue in it and I corrected it... thus I included the reason for it. LIke this one has the edit tags as well because I am editing it after it was posted and am showing what is being changed.

[/edit]

[;TT]

Then PM me them please. =)

[Soda_Popinsky]

I've got 4's password, and I've got 5 and 6 cracked so any password works, but I can't get them to spit out the actual passwords.

So I guess I did 4 legit, but 5 and 6 I "technically" cracked. In a week or so I'll post how I did it if anyone cares.

[sec_ware]

Exercise 1-3 can be solved using a hex-editor, even Exercise 4.
5 and 6 need to be decompiled (I refer to the prg PE Explorer I recommended
in this thread).
While 5 needs some basic asm knowledge, 6 is the first "real" one to crack.
The password is protected using an algorithmic procedure, although also
in a basic way: You'll end up with 9 non-linear equations,
but you have to determine a number of unknowns that is less than 9.
Although I could not get one of the equations right (never saw an asm construct
like that ), one can solve for the Password. It's not easy, but feasible.

I can give more help, even publish the passwords, but I think it was lepricauns
effort to make them, so he should decide and publish hints as he wants.


Just a note: The passwords can be cracked by brute-force in just a few minutes.
But I think that's not the goal here.
Oups, this is one hint about the structure of the password. Sorry lepri

[lepricaun]

[EDIT]crackit_7.exe is now available! this took me all day to code, so i would like to see it get cracked ;-)[/EDIT]

lepricaun: Nice little exercises. Might I suggest a solutions page? I realize that there are many different ways to solve your challenges... but a general solution for those not too familiar? I tried the first few and found them pretty easy using a hex editor or even notepad.

I'm not a programmer by any means (I know the basics of C/C++, etc.) and will surely find them a nice challenge as I progress. However, if I am unable to complete the challenge, I would be interested in relevant reading material. Don't give me the answers, just point me in the right direction. I'm learning a bit of Intel ASM in one of my "hybrid" classes now, but we are not that far... focusing on hardware and computer org. more than programming ASM. More ASM to come later in the semester.

that would be a good idea, but then the ones solved it should bive my a text on how they did it. cause to be honest, i can solve 4 and maybe five, but 6 is also to difficult for me yet

I'll swallow my pride... I got up to 4 and dropped out dead like a fish. I'm guessing decompiling the code is necessary so how about posting your answers for I am curious now.

the 4th one can be solved by following the program in memory. just get ollydbg and set breakpoints at the password testing points, and then slowly step through it, this way character for character, the password should become visible. (this also goes for the 5th).
only the 6th is really a pain in the ass (for me at least!). this one i can not give you any hints, the only one who has solved it (or in his words almost) is sec_ware. so he's the only one who can give you a hint on how to crack it.

So I guess I did 4 legit, but 5 and 6 I "technically" cracked. In a week or so I'll post how I did it if anyone cares.

you've altered the JNZ's to JE. that's possible with all ones, but only the first will spit out the real password with this technique

I can give more help, even publish the passwords, but I think it was lepricauns
effort to make them, so he should decide and publish hints as he wants.

well hints are given for the 4th and 5th. the 6th i leave up to you, since you are the only one that cracked it.

Just a note: The passwords can be cracked by brute-force in just a few minutes.
But I think that's not the goal here.

of course they can. the next one will probably be one with both a username and a password, so we rule out the bruteforce option as well.

but on the other hand, brute-forcing isn't cracking. You will not learn anything about RE if you use this technique.

i'm glad to see you guys have so much fun with them! this is a nice motivation of creating more of them


[EDIT]crackit_7.exe is now available! this took me all day to code, so i would like to see it get cracked ;-)[/EDIT]

[Soda_Popinsky]

I guess I'm the cheapest cracker ever. I couldn't get the password for 7, but again I was able to at least bypass the login.

EDIT: I got 5 cracked (I got the pass, instead of breaking the login), this is really fun.

now onto 6!