What Are Macro Viruses? And Can Windows Defender Protect You From Them?

When it comes to protecting your device from viruses and malware, it’s important to understand that they aren’t all the same. Online activities that could land you with a Trojan Horse aren’t the same that would result in you getting spyware.

And while some viruses are more infamous than others, lesser-known viruses aren’t less dangerous. One example is macro viruses. But what are macro viruses, how do they work, and how can you avoid or get rid of them?

What Is a Macro Virus?

In order to understand what a macro virus is, you first need to understand macros themselves. A macro, short for macroinstruction, is a rule that translates a specific sequence of input into a suitable output.

Think of it like a shortcut that your computer takes to run simple and relatively predictable tasks faster and more efficiently. Macros can be anything from mouse movement and keyboard strokes to direct commands.

Macro viruses can infect any software that uses the same language as them, but they often target Microsoft Word and Excel. And since macro viruses infect specific types of software instead of the operating system, they can affect any device with compatible software like Windows, macOS, and even Linux.

In the 1990s and early 2000s, there were several different types of macro viruses: chiefly, the Concept and Melissa viruses. Concept was the first macro virus that targeted Microsoft Word files, while Melissa was mostly email-borne, and first appeared a few years after Concept.

How Does It Work?

A malware warning

The dangerous thing about macro viruses is that they lie completely inactive until you run the software they’re attached to. The longer the virus remains dormant on your device, the trickier it is to find out how you first caught it.

Macro viruses infect by embedding code into macros that are linked to files and documents on your device. But until you run the software to read the infected file, it won’t budge or do any harm to your wider system.

As soon as you run the file, the virus runs too, sending out a sequence of actions automatically just like a non-malicious macro in your software would. While the primary goal of the macro virus varies depending on the intentions of its creator, most macro viruses do what all other viruses do: replicate and spread.

Once the virus starts, it’s hard to stop it. Most will begin infecting other documents on your device. However, not all of them are only concerned with multiplying.

Some macro viruses damage your files and text documents by jumbling the words inside, rendering them useless. Furthermore, some can gain access to your email account and send replicas to your contacts.

In fact, that’s how most people get infected with a macro virus: through an infected or a phishing email. But you could also get them by downloading files from untrustworthy websites.

How to Avoid Macro Viruses

virus scan

Macro viruses mostly spread via files that run through applications using macros. There are two approaches you can take to protect yourself from macro viruses.

Adjust Your Online Behavior

You can download a file infected with a macro virus from anywhere. It could also get to you through a phishing email or a seemingly legitimate message from friends or family who were infected themselves.

Also, you can infect your device by downloading .doc and .xls files from suspicious websites.

If you regularly find yourself downloading files, maybe for school or work, your best bet would be to disable macro scripts entirely. While that might limit the functionality of software like Microsoft Word and Excel, they aren’t necessary. Office applications generally stop downloaded macros by default, preferring a “Protected View”.

Relying on Cybersecurity

Whether you pride yourself on your digital hygiene or not, cybersecurity software and protective measures can cover for you when you slip up.

If you regularly use Microsoft Office apps, which are the primary target for most macro viruses, consider activating the macro security function in Microsoft Office apps.

Make sure your software is up to date. The security of older versions might not be able to intercept and detect newer macro viruses.

Most modern antivirus suites can detect macro viruses in files and alert you before downloading or attempting to run them. Some even go as far as to warn you from accessing possibly harmful links and websites.

Can Windows Defender Alone Protect You From Macro Viruses?

Turn Off Windows Defender Featured

Before you start looking for highly specific antivirus and anti-malware software and disabling features in apps you regularly use, what about the default protection in Windows?

Microsoft expanded the reach of its Windows Defender Application Guard technology beyond Microsoft Edge and into macro-reliant applications like Microsoft Word, Excel, and PowerPoint.

Application Guard utilizes hardware virtualization to run macro files in a secluded sandbox. There, you can view, edit, save, and even print documents without leaving Protected View. That way, even if you run a file infected with a macro virus, it won’t spread to other files on your device.

Outside the Protected View mode, Windows Defender can still detect macro viruses. Upon running an infected file, you’ll receive a message from Windows Defender letting you know that a threat was found. This time, however, it’ll block the file from running to stop the virus from activating.

How to Remove a Macro Virus From Your Device

Whether the macro virus was activated and started replicating or you were able to detect it early on, it’s critical that you remove it entirely from your device. Luckily, you can use Windows Defender to clean your device of malware and viruses easily.

Prepare for some of your files to be deleted, especially if the virus spread to them and you weren’t able to catch it early on. Use Windows Defender’s real-time scanning feature to pinpoint the location and any possible casualties of the macro virus.

This procedure should also alert you to any other viruses, malware, and spyware that may be lying dormant on your device.

Run Scans Regularly

Even if you’re a careful person online, you can still slip up or encounter a new and intricate scheme that tricks you into downloading a macro virus. It’s important to run regular scans whenever you’re not using your device to weed out any suspicious files before they become a problem.

How to Turn on Microsoft Defender Antivirus and Enable Real-Time Protection

Switching Microsoft Defender on is a simple process. Here’s how.

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