Question

Differentiate between a Computer Virus, Worm, and Trojan Horse.

Hint:

Virus = Needs host file. Worm = Self-spreading malware. Trojan = Fake software hiding malicious intent.

Answer 1

Concept: Computer malware refers to malicious software designed to harm, disrupt, or gain unauthorized access to computer systems. Virus, worm, and Trojan horse are common types of malware with different behaviors and methods of spreading.

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Difference Between Virus, Worm, and Trojan Horse: \[ \begin{array}{|c|c|c|c|} \hline {Basis} & {Virus} & {Worm} & {Trojan Horse} \\ \hline \text{Definition} & \text{Malicious code attached to files} & \text{Self-replicating standalone malware} & \text{Malicious program disguised as useful software} \\ \hline \text{Dependency} & \text{Needs a host file/program} & \text{Independent, no host needed} & \text{Appears as legitimate software} \\ \hline \text{Replication} & \text{Spreads when infected file runs} & \text{Spreads automatically across networks} & \text{Does not self-replicate} \\ \hline \text{User Action} & \text{Requires user execution} & \text{Spreads without user action} & \text{User installs unknowingly} \\ \hline \text{Damage} & \text{Corrupts files or system} & \text{Consumes bandwidth, slows systems} & \text{Steals data or gives unauthorized access} \\ \hline \end{array} \] 

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Explanation:

• Computer Virus: Attaches itself to a legitimate program or file and spreads when the infected file is executed. It can corrupt data and affect system performance.
• Worm: A self-replicating malware that spreads automatically across networks without needing a host file or user action. It mainly affects network performance.
• Trojan Horse: A harmful program disguised as useful software. It tricks users into installing it and then performs malicious activities such as data theft or backdoor access.

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Conclusion: A virus requires a host file and user action, a worm spreads independently across networks, and a Trojan horse disguises itself as legitimate software to deceive users and gain unauthorized access.