The PAGE_GUARD Anti-Dumping Trick (Method 2)

//http://waleedassar.blogspot.com - (@waleedassar)
//Code to show how to use the "PAGE_GUARD" anti-dumping trick.
#include "stdafx.h"
#include "windows.h"


#pragma data_seg("walied4")
int x=1;
#pragma data_seg()

unsigned long touch;



int __cdecl Handler(EXCEPTION_RECORD* pRec,void* est,CONTEXT* pContext,void* disp)
{
    unsigned long old;
    if(pRec->ExceptionCode==0x80000001)
    {
        touch=0;
        VirtualProtect(&x,0x1000,PAGE_READWRITE|PAGE_GUARD,&old);  //restore PAGE_GUARD
        *(unsigned long*)((unsigned char*)pContext+0xB8)=((unsigned long)(pRec->ExceptionAddress))+10;
        return ExceptionContinueExecution;
    }
    return ExceptionContinueSearch;
}

void __stdcall watch()
{
    __asm
    {
        push offset Handler
        push dword ptr fs:[0]
        mov dword ptr fs:[0],esp
    }
    while(1)
    {
        touch=1;
        __asm
        {
              mov dword ptr[x],1  ; //Should trigger 0x80000001
        }
        if(touch) break;
    }
    ExitProcess(0);
}

int main(int argc, char* argv[])
{
    unsigned long fake_base=(unsigned long)(&x);  //the page is initially PAGE_COPYWRITE
    *(unsigned long*)fake_base=0xCECECECE;        //Now it is PAGE_READWRITE
    unsigned long old;
    VirtualProtect((void*)fake_base,0x1000,PAGE_READWRITE|PAGE_GUARD,&old);
    unsigned long tid;
    CreateThread(0,0x1000,(LPTHREAD_START_ROUTINE)&watch,0,0,&tid);
    //---------------Useless stuff--------------
    MessageBox(0,"Try to dump me","waliedassar",0);
    ExitProcess(0);
    return 0;
}