Boot sector virus, also known as boot-infecting virus, is a malicious software program designed to infect the master boot record (MBR) of a computer’s hard disk. The MBR is located in the first sector of the hard drive and contains the necessary code to start the computer’s operating system in order to boot up the computer.
The virus is generally placed in the MBR of a computer’s hard disk, erasing the original information and replacing it with its own malicious code. This code then takes control of the boot processes, preventing the computer’s operating system from starting up properly. As a result, the operating system is unable to run and the user can no longer access the system or programs.
A disk utility program may be able to restore the MBR to its original state; however, doing so does not necessarily remove the virus. As such, it is important to scan the system with an updated antivirus program in order to identify and remove the virus.
Boot sector viruses can spread to other computers or systems in a number of ways, including diskettes or USB drives, downloading malicious software, or when an infected diskette is inserted into a clean system. Additionally, due to their ability to bypass security measures, boot sector viruses can easily take advantage of unpatched systems or security flaws, making them difficult to detect and remove.
Fortunately, boot sector viruses can be prevented by using an up-to-date antivirus program, keeping patches and security updates current, never inserting unknown or untrusted diskettes into the system, and always scanning the system for malware. Boot sector viruses are just one type of malicious computer program, but can be incredibly damaging if left unchecked.