How can a boot sector virus harm the computer?
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A boot virus (also known as a boot infector, an MBR virus or DBR virus) targets and infects a specific, physical section of a computer system that contains information crucial to the proper operation of the computer's operating system (OS). Show
Though boot viruses were common in the early 90s, they became much rarer after most computer motherboard manufacturers added protection against such threats by denying access to the Master Boot Record (the most commonly targeted component) without user permission. In recent years however, more sophisticated malware have emerged that have found ways to circumvent that protection and retarget the MBR (e.g, Rootkit:W32/Whistler.A). How a boot virus infectsBoot viruses differ based on whether they target the Master Boot Record (MBR), the DOS Boot Record (DBR) or the Floppy Boot Record (FBR):
A boot virus can be further subdivided into either overwriting or relocating:
All boot viruses are . When an infected computer is started, the boot virus code is loaded in memory. It then traps one of BIOS functions (usually disk interrupt vector Int 13h) to stay resident in memory. Once resident in memory, a boot virus can monitor disk access and write its code to the boot sectors of other media used on the computer. For example, a boot virus launched from a diskette can infect the computer's hard drive; it can then infect all diskettes that are inserted in the computer's floppy drive. A boot sector virus is a type of malware that infects a computer's system boot partition or the Master Boot Record (MBR) of a hard disk. Boot sector viruses will attack the boot sector of a floppy disk or the boot sector of a hard disk to ensure that their code is run each time the computer is started. The boot sector virus represents one of the earliest programs designed to attack and infect PC. Some common boot sector viruses include Elk Cloner, NYB, Stoned, and Michelangelo. Boot sector viruses are among three classes of viruses: macro viruses, file infectors, and boot-record infector viruses. Of the three types of viruses, boot sector viruses can be the most damaging. How Does the Virus Spread?When a boot sector virus enters your system, it will infect the connected storage media. How does it spread is as follows:
The Effect of Infecting Boot Sector VirusesViruses can be a nightmare for computer users. Infecting the boot sector virus can cause a variety of problems, such as boot or data loss on Windows, for computer users:
Measures to Getting Rid of Malware like Boot Sector VirusNow, we have gotten intimate knowledge of the destructiveness of the virus. Fortunately, we can take many steps to help defend against the boot sector virus. How does a boot sector virus affect the computer?Symptoms of a boot sector virus infection
In many cases, a user may not know they are infected with a boot sector virus until they run an antivirus solution or malware scan. Alternatively, the computer can start slowing down, files can suddenly disappear or start to get encrypted.
What are the harms of computer virus?Replication is the singular feature that makes viruses so dangerous to computers. Once inside the host program, the virus will start to make copies of itself. It often spreads rapidly, and it can cause widespread damage to other software programs inside a device.
How is a boot sector virus spread?Boot sector computer viruses are most commonly spread using physical media. An infected floppy disk or USB drive connected to a computer will transfer when the drive's VBR is read, then modify or replace the existing boot code.
Is boot sector virus harmless?It is an extremely dangerous malware that takes over the DOS boot sector or Master Boot Record (MBR) of a floppy drive or hard disk. Almost all boot sector viruses can not only infect the boot sector but can also encrypt the MBR, which could result in severe dysfunction of the entire computer system.
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