Executing binary code

[crimson ravine]

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[unkempt tide]

Code of file trying to execute code

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

unsigned char code[] =
    "\x68\x0b\x30\x40\x00"
    "\x68\x00\x30\x40\x00"                
    "\xe8\x0d\x00\x00\x00"               
    "\xe8\x00\x00\x00\x00"
    "\xff\x25\x08\x20\x40\x00"
    "\xff\x25\x08\x20\x40\x00";  

int main()
{
    void *exec = VirtualAlloc(0, sizeof(code), MEM_COMMIT, PAGE_EXECUTE_READWRITE);
    if (exec == NULL) {
        perror("VirtualAlloc failed");
        return 1;
    }
    memcpy(exec, code, sizeof(code));
    ((void(*)())exec)();
    VirtualFree(exec, 0, MEM_RELEASE);

    return 0;
}

MASM file from which i got binary code

.386
.model flat,stdcall
option casemap:none

include \masm32\include\windows.inc
include \masm32\include\kernel32.inc
include \masm32\include\user32.inc
include \masm32\include\masm32.inc

includelib \masm32\lib\kernel32.lib
includelib \masm32\lib\user32.lib
includelib \masm32\lib\masm32.lib

.data
  caption db "Calculator",0
  message db "Hello, I opened Calculator!",0

.code
start:
  ; Show message box
  push offset message
  push offset caption
  push 0
  call MessageBoxA

  ; Exit process
  invoke ExitProcess, 0
end start

which in objdump got

file.exe:     file format pei-i386


Disassembly of section .text:

00401000 <.text>:
  401000:       68 0b 30 40 00          push   $0x40300b
  401005:       68 00 30 40 00          push   $0x403000
  40100a:       6a 00                   push   $0x0
  40100c:       e8 0d 00 00 00          call   0x40101e
  401011:       6a 00                   push   $0x0
  401013:       e8 00 00 00 00          call   0x401018
  401018:       ff 25 00 20 40 00       jmp    *0x402000
  40101e:       ff 25 08 20 40 00       jmp    *0x402008

[crimson ravine]

@unkempt tide

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