___________viruses are embedded in a system’s memory so it can be reactivated if the original virus is deleted?

Correct option is B

Resident viruses are a type of malware that embeds itself into the system's memory. Once activated, they remain in the system's memory, allowing them to reactivate even if the original infected file is deleted. These viruses load into the system's RAM and run continuously in the background.

Since they reside in memory, they can infect other files and processes without relying on the original source file.

Important Key Points:

1. Resident Viruses:
• These viruses load themselves into the system’s memory (RAM).
• They can reactivate or infect files even after the original virus file is deleted.
2. Impact of Resident Viruses:
• They are harder to detect and remove because they do not need a host file to remain active.
• They can slow down system performance and corrupt files.

Knowledge Booster:

1. Why Not Other Options?
• a) File Virus:
• Incorrect. File viruses attach themselves to executable files (e.g., .exe), but they do not persist in memory after deletion.
• c) Polymorphic Virus:
• Incorrect. Polymorphic viruses can change their code to evade detection but are not necessarily memory-resident.
• d) Roolkit (Typo for Rootkit):
• Incorrect. Rootkits are advanced malware that hide malicious activities but are not specifically designed to reactivate after file deletion.
2. Behavior of Resident Viruses:
• They infect system files, background processes, or memory locations.
• Resident viruses can reinfect other programs without re-executing the original virus.
3. Examples of Resident Viruses:
• CMOS Virus: A resident virus that infects the system's BIOS or CMOS memory.
• Randex Virus: Infects system memory to spread through networks.
4. Interesting Fact:

Resident viruses are among the oldest types of viruses and are still used today due to their persistent and stealthy nature.