Virus vs. Malware: What's the Difference?

Malware includes all types of threats to your computer, including viruses.

Image of a malware alert on a computer screen

solarseven\Getty Images 

The terms malware and virus are sometimes used interchangeably, but there are differences worth knowing. Here we cover those differences as well as tips to help protect your computer from all types of malware.

Overall Findings

Malware is an umbrella term covering nearly every threat a connected computer or mobile device may face. It includes all of the following:

  • Virus: A program that, once downloaded to a system, can replicate itself. It does this by automatically modifying existing software or by inserting its own computer code.
  • Trojan: A program that portrays itself as a useful application in a ploy to convince users to download it, much like the Trojan horse of Greek mythology. Once downloaded and activated, Trojans perform harmful or destructive functions.
  • Worm: A program that self-replicates like a virus but can do so throughout a computer network. Once downloaded to a host computer, a worm can make copies of itself and spread to other computers on a network, stealing data or corrupting files.
  • Backdoor: Taking advantage of vulnerabilities, backdoors are used to circumvent normal authentication or security measures. Backdoors usually target web servers with a remote "injection" of a malware script, which then stays on the server and allows hackers to remotely access the system and its files.
  • Exploit: An application written specifically to exploit a known bug or vulnerability on a system. These are often known as "zero-day exploits" because they attack software vulnerabilities that are identified but not yet patched.
  • Adware: An application that installs itself on your computer with the purpose of automatically generating advertisements that appear while browsing the web.
  • Potentially Unwanted Programs (PUP): An application that downloads itself alongside a program that was meant to be installed. This may be a browser toolbar, adware, or even a bitcoin-mining app. The effect of a PUP is to use up your CPU usage without your knowledge.

Do Antivirus Apps Protect You From All Malware?

Yes and no. Also known as "on-access" tools, antivirus applications claim to protect your computer from all forms of malware. They do this by scanning files you've downloaded and websites you've visited to detect threats.

Screenshot of AVG Antivirus software

While it's true that antivirus software can protect you from malware discovered on a PC or download file, it is not a guaranteed safety net. For example, antivirus software can't do much against the zero-day exploit, which is designed to take advantage of flaws in malware prevention software.

Some programs, like Malwarebytes, offer additional layers of security by running frequent malware scans and automatically updating itself to detect new threats.

Screenshot of a Malwarebytes scan

These programs help clean up and remove malware and unwanted software, which in turn frees up memory and CPU, improving overall performance.

How to Protect Your Computer From All Malware

The best approach to ensure that your computer isn't infected with any form of malware is to use a three-layer system.

  1. Enable Windows Defender: Select the Windows start menu and type Windows Defender. Select Windows Defender settings and then select Open Windows Security. Make sure all checkmarks are green. Take any suggested actions to make sure every item has a green checkmark.

    A Screenshot of Windows Defender showing all options protected.
  2. Enable Windows Firewall: In the left navigation pane, select Firewall & network protection. Make sure the Firewall is on status is displayed under all three network types. If it isn't on, then turn on that firewall.

    Screenshot of enabled Windows Defender Firewall.
  3. Install Antivirus Software: For the second level of protection, choose and install one of the many free antivirus applications that are available. You should also install antivirus apps for your Android, as well as antivirus apps for your Mac. You may need to restart your computer to complete installation.

    Screenshot of AVG Antivirus main screen
  4. Enable Antivirus Self-Defense: In your antivirus Settings menu, you'll usually find a Self-Defense or Self-Protect feature. This ensures that virus software can't disable your antivirus app and remove its protection. Make sure this feature is enabled.

    Screenshot of AVG Antivirus Enable Self-Defense feature.
  5. Install Malware Scanning Software: These applications are also known as on-demand virus scanners. They are typically updated immediately with zero-day exploits and will ensure your computer is free of the latest threats. Install one of these apps and perform a full system scan.

    The initial full scan can take several hours to complete. Many antivirus applications are light, which means they won't drag your system down, but some may, so if you experience lag time when loading applications during a full virus scan, that may not be an unusual occurrence.

    Screenshot of Malwarebytes following a system scan
  6. Set On-Demand Scan Schedule: To ensure you're always protected from all forms of malware, set the on-demand scanner on a regular scan schedule. You can usually find this under Scan or Settings. A once-a-day scan is usually enough, but if you want, you can set the software to scan several times a day.

    Screenshot of the Malwarebytes scan schedule.

    Many people set their daily scans to run at night or very early in the morning, when the computer will not be in use. This is a throw-back to when antivirus programs were resource intense and would cause a system to slow down dramatically during a scan. It's still not a bad practice to run your scans at night, but if you turn your system off at night, you can usually schedule them for light-use daytime hours without noticing too much difference in reaction times.

  7. Enable Automatic Updates. In both your antivirus and malware-scanner applications, check the setting section and ensure that Application Updates are set to Automatic. This ensures that the moment zero-day exploits are identified, you'll receive the update that will protect your system from those.

    Screenshot of Malwarebytes application updates settings.