Topic created on: July 23, 2010 06:06 CDT by justanotherhacker .

Hello all,

Sorry to burst in like this.
But I am having a little problem RCEing this app.
Its a tiny-crackme I got from crackmes.de

This file has ptrace protection.
As viewed here:

% strace ./tiny-crackme
execve("./tiny-crackme", ["./tiny-crackme"], [/* 43 vars */]) = 0
[ Process PID=6933 runs in 32 bit mode. ]
ptrace(PTRACE_TRACEME, 0, 0x1, 0)       = -1 EPERM (Operation not permitted)
write(0, "Sorry but the process seems to b"..., 52Sorry but the process seems to be traced... Bye...
) = 52
_exit(0)  

So I wrote this: http://pastebin.com/fuAfvz03
Compiled it to a Shared-Library.
And tried to run it like this:
LD_PRELOAD=$PWD/libfakeptrace.so ./tiny-crackme
It didn't use my ptrace function.
I even tried this:
LD_LIBRARY_PATH=. LD_PRELOAD=libfakeptrace.so ./tiny-crackme


And I am all like W-T-F? I've done this trick before. And it worked. But now it doesn't.
So I hope some one here does have the time to tell me what I am doing wrong..?

Thanks in advance,
-JustAnotherHacker.