Another way to hello world

main.c

#include <stdio.h>
#include <Windows.h>

typedef int (__cdecl *PRINTF)
   (const char* _Format, ...);
typedef void (*Mystery) (PRINTF p);

void main (void)
{
	const char mystery[] =
	{
		0x55, 0x8B, 0xEC, 0x83, 0xEC, 0x10,
		0xC6, 0x45, 0xF0, 0x48, 0xC6, 0x45,
		0xF1, 0x65, 0xC6, 0x45, 0xF2, 0x6C,
		0xC6, 0x45, 0xF3, 0x6C, 0xC6, 0x45,
		0xF4, 0x6F, 0xC6, 0x45, 0xF5, 0x20,
		0xC6, 0x45, 0xF6, 0x57, 0xC6, 0x45,
		0xF7, 0x6F, 0xC6, 0x45, 0xF8, 0x72,
		0xC6, 0x45, 0xF9, 0x6C, 0xC6, 0x45,
		0xFA, 0x64, 0xC6, 0x45, 0xFB, 0x21,
		0xC6, 0x45, 0xFC, 0x0A, 0xC6, 0x45,
		0xFD, 0x00, 0x8D, 0x45, 0xF0, 0x50,
		0xFF, 0x55, 0x08, 0x83, 0xC4, 0x04,
		0x8B, 0xE5, 0x5D, 0xC3, 0x00, 0x00,
	};

	DWORD old;
	VirtualProtect ((LPVOID) mystery,
		sizeof (mystery),
		PAGE_EXECUTE_READWRITE, &old);

	((Mystery) mystery) (printf);
}

Mystery

void Mystery (PRINTF p)
{
	const char text[] =
	{
		'H', 'e', 'l', 'l', 'o', ' ',
		'W', 'o', 'r', 'l', 'd', '!',
		'\n', '\0',
	};

	p (text);
}