FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -The boot sector contains all the files required to start the operating system (OS) and other bootable programs. The viruses run at bootup, allowing them to execute malicious code during startup time–before many security layers are executed, including antivirus software.

Detailed explanation-2: -A boot sector virus is a type of malware that infects a system’s boot partition or the Master Boot Record (MBR) of a hard disk. During startup and before security software can be executed, the virus executes malicious code.

Detailed explanation-3: -Brain is a boot sector virus, infecting the first sector of floppies as they are inserted into an infected computer. Brain is only a few kilobytes in size and most of it is located in sectors that are marked as “bad” in the FAT.

Detailed explanation-4: -Boot sector viruses infect the boot sector or the partition table of a disk. Computer systems are typically infected by these viruses when started with infected floppy disks-the boot attempt does not have to be successful for the virus to infect the computer hard drive.

Detailed explanation-5: -Since the MBR executes every time a computer is started, a boot sector virus is extremely dangerous. Once the boot code on the drive is infected, the virus will be loaded into memory on every startup. From memory, the boot virus can spread to every disk that the system reads.