downloadbrowsemonkey's Crackme OS

Download CrackmeOS.zip, 520 kb (password: crackmes.de)
Browse contents of CrackmeOS.zip

Crack my OS. 2 months of coding from scratch and it all goes to waste by cracking it! Read the readme.txt.

Good luck.

Difficulty: 3 - Getting harder
Platform: Multiplatform
Language: Assembler

Published: 04. Jul, 2005
Downloads: 1126

Rating

Votes: 4
Crackme is nothing special.

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Solutions

Solution by Otton, published 06. jul, 2005; download (280 kb), password: crackmes.de or browse.

Otton has not rated this crackme yet.

Solution by ZeroCoder, published 06. jul, 2005; download (281 kb), password: crackmes.de or browse.

ZeroCoder has rated this crackme as quite nice.

Solution by bilbo, published 06. jul, 2005; download (280 kb), password: crackmes.de or browse.

bilbo has not rated this crackme yet.

Solution by TaGaDaPaF!, published 06. jul, 2005; download (276 kb), password: crackmes.de or browse.

TaGaDaPaF! has not rated this crackme yet.

The submission of solutions is closed.

Discussion and comments

Scortile
04. Jul 2005
haha, this one sounds pretty unique to me.. I think I'll give it a try some time, but not yet, I'm sure I need more time for this one than I can spare at the moment..
Oorja-HalT
06. Jul 2005
What exactly is the task.
is it
1.To change the crackme information that is displayed when the crackmeOS is selected .
2.Beside is it ok to patch the file
3. you have to create the new file
if no1 is yes and no2 is yes and no3 is no i can submit my solution
bilbo
06. Jul 2005
Well, since he doesn't indicate any constrains, I thought we can do what we like better and I submitted mine...

Anyway, I am pretty confident that it is impossible to patch directly floppy.img, do you agree?
Otton
06. Jul 2005
Hi.
I'm new here and I liked an idea of crack OS.
Unfortunately I have impression that I misunderstood the rules or monkey must be joking ;-)
Anyway, I uploaded my solution, too. We'll maybe see what will happen ;-)

[bilbo] I think so, too. Mainly because direct patching of kernel seems not possible.
Oorja-HalT
06. Jul 2005
hey guys you sre makes me lazy.Now i dont have to write a solution.And yes you cant change floppy image directly. It has to be copied in to a floppy and changed using hexeditor.
BTW do you agree that it deserves a this high rating.
monkey
Author
06. Jul 2005
Yeah. It took long enough for you to get it. Within the time it took to get the first solutions, I have made some real crack-worthy stuff. Now that I have my own API's and basically a DOS clone that runs it's own executables from a ext2 floppy, so it isn't gonna be so easy next time.
bilbo
07. Jul 2005
[b]monkey[/b], your idea deserves appreciation... I hope anyway next time you will add at least a checksum control, to force us to do some disassembly ;-)
[b]Otton, Oorja-HalT[/b], I was saying it is impossible to directly patch FLOPPY.IMG simply because the stuff to patch is gzipped!
Otton
07. Jul 2005
Hi again.
[bilbo] I meant that, too (kernel==gzip).
[Oorja-HalT] It couldn't be so hard if I could solve it ;-)
[monkey] Really nice idea. I think that coding and testing it wasn't just piece of cake. It could be fine base for something harder. First integrity checks could be made in modified stage2 code (I suspected that to be honest).
Ok. Should we start to search (code) debugger for v. 2.0 of your OS ?
Regards.
monkey
Author
07. Jul 2005
Next version is going to test your skills. Now I can run a checksum against itself, and the kernel will load objects which are in my own special format.

I suggest you read a lot of cryto stuff because as your probably know, I love crypto :)

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