The master boot record (MBR) is the first sector of the hard disk that contains some basic information about how to interpret the data stored on the disk. In general the MBR is 512 bytes long in size and contains the boot code, partition table information and the boot code signature. The boot code helps load the operating system while the partition table information helps recognize the file system stored on the disk. If the MBR gets overwritten by the wrong information or if it becomes corrupt, then the disk drive will not be recognized and if it is the system disk, then operating system will fail to load.
Some of the malware hides its code in the MBR so that it can load even before the operating system loads and can take control of the vital aspects of the operating system to further infect files and other media. Usually your antivirus software can prevent the attempts of a malicious software trying to infect the MBR, but you can also use the MBRFilter that is a disk filter that prevents writing anything on the sector 0 of any attached disks in Windows.
The MBRFilter is a very simple disk filter that you can download and install from its GitHub page. You have to download the 32-bit or 64-bit version depending on your Windows operating system version. Then you can extract the archive file contents, right-click on the MBRFilter.inf and choose Install from the context-menu. After this you can reboot and you are all done.
In case you make a mess of your hard disk’s MBR and you can no longer boot into Windows, do not worry – you can fix it easily. You will need a bootable Windows 10 DVD or USB disk. Boot from this installation disk. On the install screen, choose Repair your computer, then Troubleshoot, then Command Prompt and then give the following command: bootrec /fixmbr followed by bootrec /fixboot.
Conclusion: MBRFilter can be useful in protecting the MBR sector in your disks. It will not let any program good or bad, write to the sector 0 of the storage disks.
You can download MBRFilter from https://github.com/vrtadmin/MBRFilter/releases.