Explain the difference between Virus and Worm?

Most people consider a computer virus and a computer worm as equivalent. Although their primary aim is to create havoc by infiltrating a system, the way they attack, spread, and replicate sets them apart.

In this post, we would walk through in detail what the computer virus and the computer worm are and how they are different from each other.

What is a Virus

A virus is one of the most common and oldest computer malware. Like a biological virus spreads from human to human and damages their body, a computer virus spreads from computer to computer and corrupts user files, documents, and other data. It replicates by attaching itself to a file or program and altering its codes.

After infiltrating a computer, it can rapidly replicate itself. However, it does not spread by itself and requires a source to spread from one system to another. Other than the host, it also needs human intervention for spreading. Once it gets attached to the host, it can be spread through pen drives, emails, or similar means.

After a person transfers the host file to another computer, the virus replicates on that system too and damages the files and applications. Some viruses can even delete, modify, and duplicate files.

What is a Worm

A worm is a malicious program that, like a computer virus, spreads from system to system and replicates itself after the infiltration. However, unlike viruses, worms do not require a host or human intervention to spread. It takes advantage of the security failures in the network to spread itself.

A worm is generally designed to increase the system resource usage and cause system failure and network crash. To enter any other system from the current system, a worm finds vulnerabilities or loopholes and uses them to its advantage.

Once a worm enters a system, it spreads through the network and can reach the other networks the device is connected to. Since it does not require any host or human intervention, it typically spreads faster than viruses.

Difference between Virus and Worm

Based on the spreading method, damage caused, and other factors, viruses and worms are different in the following ways −


  • A virus attaches to a host file and spreads to the system wherever the host reaches.

  • It needs human intervention to spread from one system to another, like email, pen drives, hard drives, and others.

  • The spreading speed of the virus is slow as compared to the worm.

  • After infiltrating a device, a virus can damage any file, delete it, alter it, or create its duplicate. Basically, its attack is on system files and applications.

  • To remove a virus and stop its spread, users need to install an antivirus or antimalware program.


  • Worms do not attach themselves to the host; instead, they exploit the network vulnerabilities to spread.

  • It automatically spreads through networks without any intervention.

  • The worm spreads faster as it spread through networks.

  • After entering a system, a worm uses its resources to slow it down and eventually crash it. Basically, its purpose is to crash the system and network.

  • To get rid of the worm and block its spread, users need both an antivirus/antimalware and a network firewall.

How to stay protected from Viruses and Worms?

It is better to stay protected from Viruses and Worms instead of dealing with them after their infection. Here are some preventive tips −

  • Never download the computer programs from unofficial, untrustworthy sources.

  • Always have a robust security solution installed on your device and make sure that it comes with a firewall.

  • When you insert any Pendrive or any other USB drive on your system, make sure that you have thoroughly scanned it with a security solution like antivirus or antimalware before transferring any files from it to your device.

  • Avoid opening emails and downloading attachments sent from unknown or untrustworthy sources.

Updated on: 07-Jun-2021


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