prukes on 2023-09-24 20:24:
Hi, I've been trying to do this crackme, yet i get stuck at the very start. This all is very new to me, since I've started a couple days ago and this was pretty much my first windows crackme. I managed to figure out that there is some control flow guard initialization with security_cookie? but i can't even find the main method. Would anyone be so kind and guide me the right way?
cnathansmith on 2023-09-26 16:40:
You search for the error message or call to MessageBoxA or W and trace your way back. I wouldn't start with this one, though, there's something really subtle going on that's hard to work out. Try one of the low difficulty rated console-based challenges.
cnathansmith on 2023-09-27 17:10:
I hope you don't mind me talking through where I'm at with this a bit, but I've been stuck on one part for days and can't see a way around it.
The response has to be in the same format as the challenge.
The '-' separated sections of it are broken up and built into two identical CLists.
Several registers are populated with the atoi() version of each section from one list, then 3 other registers are set to the first 3 numbers from the other list.
Then math is performed, one part of which has to satisfy: (atoi(CList1[0]) - atoi(CList2[0])) % 0xea == 0x84, but this can never be true when CList1[0] == CList2[0].
I have been pouring over all the assignments and the list building function and cannot for the life of me figure out what would ever cause these lists to be populated with different values
samir3216 on 2023-10-12 02:37:
So this is very very hard,i've got source code on ghidra,maybe this can help.
https://pastebin.com/raw/xC0smupv
SUPERNOVA on 2023-11-05 19:13:
@cnathansmith, these numbers are generated based on your hardware identifiers, like disk serial numbers, bios information etc, but I still can't get to the part where those numbers are validated. Maybe someone can give us a hand here
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