You can download the official firmware for the directly from the official teXet support site or community forums like 4PDA. Official Download Links

Ensure you install the MediaTek VCOM drivers first. If using Windows 8 or 10, you may need to disable driver signature enforcement .

Always perform a backup of your current system and IMEI before flashing, as the process may involve a factory reset . teXet TM-4072 - Прошивка MIUI v5 (OS 4.2.2) - 4PDA

Detailed instructions and stock ROMs are available on the teXet TM-4072 4PDA Forum .