Which type of computer virus infects the boot sector of a storage device so that it takes control when the system starts and can destroy or corrupt information?

Introduction / Context:
Computer viruses can target different parts of a system, such as application files, documents or critical system areas. One particularly dangerous type of virus attacks the boot sector, the part of a disk that contains code used during startup. Because this sector is executed when the computer boots, such viruses can take control early and interfere with system operation. This question asks you to identify the category name for viruses that infect the boot area of disks and thereby overtake the system at startup.

Given Data / Assumptions:

• The virus overtakes the computer system when it boots.
• It can destroy or corrupt information on the storage device.
• The infection is associated with the boot process and boot sector.
• Options list several recognised categories of malware.

Concept / Approach:
Boot sector viruses, often called boot infectors, specifically target the boot sector or master boot record of disks. When the computer attempts to start from an infected disk, the virus code runs first, before the operating system. This allows it to load into memory and potentially spread to other disks or disrupt normal operation. System infectors and macro viruses focus on different components, Trojans rely on disguise, and stealth viruses try to hide their presence but are not defined solely by boot sector infection. Therefore, the correct category is boot infector virus.

Step-by-Step Solution:

Verification / Alternative check:
Descriptions of classic viruses like the Michelangelo virus identify them as boot sector viruses that infect the master boot record. Technical articles explain that when an infected disk is used to start a computer, the virus code is loaded into memory first. After that, even clean disks inserted later may be infected. Anti virus tools often have explicit checks for boot sector infections. In classification tables, the term boot infector or boot sector virus is consistently used for this type of threat, confirming the answer.

Why Other Options Are Wrong:

• System infector virus: This broad term can describe viruses that infect system files, but the question specifically points to boot sector behaviour.
• Trojan horse: Relies on tricking the user into running a seemingly useful program; it does not specifically infect the boot sector by definition.
• Stealth virus: Designed to hide its presence by intercepting system calls, but it may infect different areas and is not defined solely by boot sector infection.
• Macro virus: Infects macro code in applications like word processors and spreadsheets, usually spreading through documents rather than boot sectors.

Common Pitfalls:
Students sometimes pick Trojan horse whenever they see the word destroy or virus because it is a familiar term. Others confuse stealth viruses, which hide, with boot viruses, which run early at startup. A simple way to remember is that anything that acts at boot time and lives in the boot sector is a boot infector, while Trojans are about disguise and macros are about document scripts. Keeping these categories clear helps in both exams and understanding how different malware behaves.

Final Answer:
The virus that infects the boot sector and overtakes the system when it starts is called a boot infector virus.