What Is the Difference Between a Computer Virus and a Worm?

Experts strongly encourage computer users to pay close attention to their cybersecurity. However, when you go online searching for more information on the subject, you see people talking about malware, viruses, Trojans, worms, and whatnot. 

We know that the cybersecurity subject can be confusing. That’s why we have prepared a beginner-friendly information guide to help get accustomed to the terminology used in the cybersecurity industry.

In this article, we will take a closer look at two malware categories, viruses and worms, and explain what measures you can take to protect from such unwanted intruders.

Differences Between Worms and Viruses

The easiest way to distinguish the viruses from the worms is to take a look at the way these threats spread. 

The computer virus needs a host to infect computers. It inserts its malicious code (payload) into a file or program and will then proceed to steal your computer resources to spread on the OS.

A computer virus lives within the host and needs human interference to execute. In other words, the virus lies dormant until you execute the corrupted file. You could come in contact with such infected files by downloading them off the Internet, through email and other messaging platforms.

Once activated, the virus will start self-replicating, copying itself and spreading.

Viruses could cause damage, such as corrupting files and programs, affecting your computer performance, and infecting more devices. 

A computer worm is different from a virus. It doesn’t require a host nor human interaction to spread. The worm is self-replicating malware that usually leverages software vulnerabilities. 

A software vulnerability could be created accidentally during the software development stage. Hackers later discover these vulnerabilities and develop tools to exploit them. 

Hackers use exploits to push malware through vulnerable software and infect your computer without you noticing anything. The worm can also reach your computer through an infected program or file. 

Once the worm is on the system, it will scan the local network for connected devices that contain the same vulnerability. The threat will then jump to all vulnerable devices and repeat the process. 

The worms are particularly dangerous as they can infect your device when you connect to a public network, such as a local café’s Wi-Fi. 

Similarities Between Worms and Viruses

The main similarity between worms and viruses is that both threats are self-replicating and spread rapidly. 

Both worms and viruses have the potential to cause security and privacy problems, with minor infections damaging files and causing software crashes, and major infections leading to data exfiltration, which then lead to identity frauds and monetary theft.

Businesses, healthcare providers, and governments could also be hit by worms and viruses, with large-scale malware costing millions to repair and occasionally causing cyberwarfare. 

What to do if your computer is infected with a virus or worm

The most common symptoms of virus and worm infections are:

• Unexplained slow performance.
• Frequent OS freezes and crashes.
• Settings alterations you didn’t perform or authorize. 
• Missing or corrupted files.
• Sudden loss of storage space.
• Tons of pop-ups.

If your device has any of these symptoms, use powerful antivirus software to perform a system scan. If malware is detected, take measures to remove it.

NOTE: If you don’t have experience in removing malware, it is recommended that you use malware removal software, which is developed to safely eliminate the threat without damaging the operating system.  

Useful Tips

Hackers use innovative tricks to develop and spread their malicious software. However, there are steps anyone can take to prevent or at least limit malware infections. 

• Do not open suspicious emails. Treat all unexpected emails and messages from unknown sources as potentially malicious. Be especially careful with links and attachments as they could deliver malware.
• Download apps and files from reputable sources. App marketplaces, such as Google Play, Apple App Store, and Microsoft Store offer software that is tested for security issues. While these sources are not 100% foolproof, they are much safer than third-party download platforms. Similarly, you can also download software from its official website.
• Use an adblocker. Malicious ads (malvertising) could also deliver malware to your computer. Use an adblocker tool to limit the chance of accidentally clicking on a malicious advertisement.
• Don’t connect to Public networks. While the unsecured public networks could seem a great option to save data bandwidth, these networks are often targeted by hackers. If you absolutely need to use such networks, use a VPN or virtual private network to protect yourself.
• Use Antivirus Software. There are countless cyberthreats that are targeting unprotected devices. Running an antivirus tool is a great help in the fight against malware.
• Keep your OS and apps up-to-date. Software and OS updates deliver security patches, bug fixes, and software enhancements. By running the latest version of your software, you ensure that your computer is patched for all known security vulnerabilities.