MultiMS.h

#include <winternl.h>

typedef enum _OBJECT_INFORMATION_CLASS {
	ObjectBasicInformation   = 0,
	ObjectTypeInformation    = 2
} OBJECT_INFORMATION_CLASS;

typedef NTSTATUS (NTAPI *NtQuerySystemInformation_t) (SYSTEM_INFORMATION_CLASS SystemInformationClass, PVOID SystemInformation, ULONG SystemInformationLength, PULONG ReturnLength);
typedef NTSTATUS (NTAPI *NtQueryObject_t) (HANDLE Handle, OBJECT_INFORMATION_CLASS ObjectInformationClass, PVOID ObjectInformation, ULONG ObjectInformationLength, PULONG ReturnLength);

struct SYSTEM_HANDLE_INFORMATION
{
	DWORD pid;
	BYTE type;
	BYTE flags;
	WORD handle;
	DWORD object;
	DWORD access;
};

typedef struct _OBJECT_NAME_INFORMATION {
	UNICODE_STRING Name;
} OBJECT_NAME_INFORMATION, *POBJECT_NAME_INFORMATION;

bool EnableMultiMS()
{
#ifdef VMProtectSDK
VMProtectBegin("MultiMS");
#endif
	int handleCount = 1024;

	HMODULE ntdll = GetModuleHandleW(L"ntdll");
	if (ntdll == NULL)
	{
		//Log(L"Couldn't get ntdll handle\n");
		return false;
	}

	NtQueryObject_t ntQO = (NtQueryObject_t)GetProcAddress(ntdll, "NtQueryObject");
	NtQuerySystemInformation_t ntQSI = (NtQuerySystemInformation_t)GetProcAddress(ntdll, "NtQuerySystemInformation");
	if (ntQO == NULL || ntQSI == NULL)
	{
		//Log(L"Couldn't find procedures for MultiMS (%x / %x)\n", ntQO, ntQSI);
		return false;
	}

	struct HandleInfoSet
	{
		unsigned int count;
		SYSTEM_HANDLE_INFORMATION handles[1];
	};

	HandleInfoSet *infoSet = (HandleInfoSet *)malloc(4 + sizeof(SYSTEM_HANDLE_INFORMATION) * handleCount);
	DWORD length;

	NTSTATUS status = ntQSI((SYSTEM_INFORMATION_CLASS)16, infoSet, 4 + sizeof(SYSTEM_HANDLE_INFORMATION) * handleCount, &length);

	//Log(L"alloc with %i // %i\n", handleCount, handleCount * sizeof(SYSTEM_HANDLE_INFORMATION) + 4);

	while (status == (NTSTATUS)0xc0000004) //STATUS_INFO_LENGTH_MISMATCH
	{
		free(infoSet);

		handleCount *= 2;

		//Log(L"alloc with %i // %i\n", handleCount, handleCount * sizeof(SYSTEM_HANDLE_INFORMATION) + 4);
		infoSet = (HandleInfoSet *)malloc(4 + sizeof(SYSTEM_HANDLE_INFORMATION) * handleCount);
		status = ntQSI((SYSTEM_INFORMATION_CLASS)16, infoSet, 4 + sizeof(SYSTEM_HANDLE_INFORMATION) * handleCount, &length);
	}

	if (status != 0) //STATUS_SUCCESS
	{
		//Log(L"Failed to enumerate handles open by this process (errorcode %x)\n", status);
		free(infoSet);
		return false;
	}

	for (unsigned int i = 0; i < infoSet->count; i++)
	{
		wchar_t nameBuffer[1024];
		//if (infoSet->handles[i].handle == 0x0012019F) continue;	// some buggy thing we need to skip
		status = ntQO((HANDLE)infoSet->handles[i].handle, (OBJECT_INFORMATION_CLASS)1, nameBuffer, 1024, &length);
		if (status != 0) //STATUS_SUCCESS
			continue;

		if (wcsstr(nameBuffer + 4, L"WvsClientMtx") != NULL)
		{
			HANDLE handle;
			DuplicateHandle(GetCurrentProcess(), (HANDLE)infoSet->handles[i].handle, 0, &handle, 0, FALSE, DUPLICATE_CLOSE_SOURCE);
			//CloseHandle(handle);
			ReleaseMutex(handle);
			//Log(L"Mutex closed, MultiMS is ok\n");
			break;
		}
	}

	free(infoSet);
#ifdef VMProtectSDK
VMProtectEnd();
#endif
return true;
}