PVOID GetSystemRoutineAddress(WCHAR *Name)
{
 UNICODE_STRING RoutineName;
 PVOID RoutineAddress = NULL;
   
 RtlInitUnicodeString(&RoutineName, Name);

 try
 {
     RoutineAddress = MmGetSystemRoutineAddress(&RoutineName);
 }
 except (EXCEPTION_EXECUTE_HANDLER)
 {
     RoutineAddress = NULL;
 }
   
 return RoutineAddress;
}

typedef NTSTATUS (*_ZwQueryInformationProcess)(__in HANDLE ProcessHandle, __in PROCESSINFOCLASS ProcessInformationClass, __out PVOID ProcessInformation, __in ULONG ProcessInformationLength, __out_opt PULONG ReturnLength);  
_ZwQueryInformationProcess ZwQueryInformationProcess;

HANDLE ProcessHandleToProcessId(HANDLE ProcessHandle)
{
NTSTATUS Status;
ULONG ReturnLength;
PROCESS_BASIC_INFORMATION PBI;

__try
   {
 ZwQueryInformationProcess = GetSystemRoutineAddress(L"ZwQueryInformationProcess");
   
 if (!ZwQueryInformationProcess)
  return (HANDLE)0;

 Status = ZwQueryInformationProcess(ProcessHandle, ProcessBasicInformation, &PBI, sizeof(PROCESS_BASIC_INFORMATION), &ReturnLength);
 if (!NT_SUCCESS(Status))
 {
  return (HANDLE)0;
 }

 ZwQueryInformationProcess = NULL;
   }
__except( EXCEPTION_EXECUTE_HANDLER )  
   {        
   }
return (HANDLE)PBI.UniqueProcessId;
}