direct_syscall.cpp

#include "pch.h"
#include <Windows.h>
#include "winternl.h"
#pragma comment(lib, "ntdll")

EXTERN_C NTSTATUS SysNtCreateFile(
	PHANDLE FileHandle, 
	ACCESS_MASK DesiredAccess, 
	POBJECT_ATTRIBUTES ObjectAttributes, 
	PIO_STATUS_BLOCK IoStatusBlock, 
	PLARGE_INTEGER AllocationSize, 
	ULONG FileAttributes, 
	ULONG ShareAccess, 
	ULONG CreateDisposition, 
	ULONG CreateOptions, 
	PVOID EaBuffer, 
	ULONG EaLength);

int main()
{
	FARPROC addr = GetProcAddress(LoadLibraryA("ntdll"), "NtCreateFile");
	
	OBJECT_ATTRIBUTES oa;
	HANDLE fileHandle = NULL;
	NTSTATUS status = NULL;
	UNICODE_STRING fileName;
	IO_STATUS_BLOCK osb;

	RtlInitUnicodeString(&fileName, (PCWSTR)L"\\??\\c:\\temp\\test.txt");
	ZeroMemory(&osb, sizeof(IO_STATUS_BLOCK));
	InitializeObjectAttributes(&oa, &fileName, OBJ_CASE_INSENSITIVE, NULL, NULL);

	SysNtCreateFile(&fileHandle, FILE_GENERIC_WRITE, &oa, &osb, 0, FILE_ATTRIBUTE_NORMAL, FILE_SHARE_WRITE, FILE_OVERWRITE_IF, FILE_SYNCHRONOUS_IO_NONALERT, NULL, 0);
	return 0;
}