_______ virus infects the first sector of disk.

The correct answer is Boot sector

Key Points

• Boot sector viruses are a type of virus that infects the boot sector of floppy disks or the Master Boot Record (MBR) of hard disks.
• These viruses are loaded into the computer’s memory when the system is booted up from an infected disk.
• Once in memory, they can spread to other disks and systems.
• Examples of boot sector viruses include the notorious "Michelangelo" and "Stone" viruses.

Additional Information

• Chernobyl (CIH) Virus: A highly destructive virus that overwrites important data on infected systems, including the BIOS.
• Logic bomb: A malicious piece of code that is triggered by a specific event or condition.
• Trojan Horse: A type of malware disguised as legitimate software to deceive users into installing it.