The Ultimate guide: how to remove worm virus on Mac

Malware is almost as numerous as the stars, and depending on its type, it can affect your computer differently. To better understand how to keep your data secure and your Mac safe, you should know how it works. In this article, we’ll look at one of the most common types of malware… the WORM!

What is a worm virus?

A worm is a specific type of malware that can replicate itself, moving from computer to computer without any intervention from the users. It doesn’t need to hook into a separate piece of software to cause problems.

Worms can infect your computer in several ways. Some exploit security flaws in software, allowing the worm to attack your device when you visit an infected website or open a file. They can also be transmitted by a spam email or message in an app like Messages or Facebook Messenger. That email or message then contains a link. If you click that link, it will take you to a website that automatically downloads the worm.

Once your computer is infected, the hacker can steal data, destroy or encrypt files, and control your computer by locking you out.

How does worm malware spread?

Worm doesn’t require a host system or user action to spread. It means it’s self-replicating but doesn't attach to a file or program. Instead, it moves through networks, from one computer to another, exploiting vulnerabilities in the network. File sharing, social networks, Instant messengers (IMs), external devices, etc., are well-known platforms for worm attacks.

What’s more, worms are more agile than viruses and can roll out more quickly. They can also seriously disrupt large networks, causing them to slow down by consuming vast bandwidth.

How can a computer worm harm your Mac?

For those of you who still think a worm is not that big of a deal, here’s the list of 6 WHYS you don’t want it on your computer, ever!

  1. It steals your data!
  2. It sneaks in other malware!
  3. It secretly deletes your files!
  4. It causes network overload!
  5. It uses up your bandwidth!
  6. It eats up space on your hard drive!

What is the difference between a virus and a worm?

Are viruses and worms the same thing? Absolutely not! The critical difference between virus and worm malware is this: viruses are activated by us humans. They won’t do your Mac any harm unless you authorize them to. And worms… well, you already know.

Though when it comes to virus vs. worm, they’re both pretty bad!

Are there any well-known examples of worms?

Several. One of the most infamous is Stuxnet — a worm developed as a joint effort by the US and Israel to target Iran’s attempts to build a nuclear weapon.

It was discovered in 2010 and was spread using a USB thumb drive. It’s believed that it targeted software controlling Iran's uranium facility. According to the New York Times, among the damage it caused was the self-destruction of 1,000 centrifuges. A programming error allowed it to escape to the wider internet, where security researchers discovered it.


Perhaps the most infamous worm of all, Koobface was one of the first malware programs to exploit the possibilities offered by social media. In 2008, social media was still in its infancy, and Facebook was relatively new. The Koobface worm infected user accounts and spread them by sending fake messages to users' friends. Those messages claimed that Flash Player on the recipient's computer was outdated and — who would doubt — contained a link to download the updater. When the user clicked the link, a computer got infected.


In 2017, WannaCry caused hundreds of millions of dollars of damage to computer networks worldwide. It combined the techniques of a worm by exploiting a vulnerability in Microsoft's SMB Version 1 file-sharing protocol, known as Eternal Blue. Any network that hadn't patched SMB Version 1 was at risk, including systems belonging to some of the largest organizations in the world.

Storm Worm

In 2006, an email with the subject line '230 dead as storm batters Europe' was unleashed. Given that such a catastrophic event is almost unheard of in Europe, many people clicked the link it contained to read more. That link inevitably unleashed malware that infected the user's computer and turned it into a bot to continue spreading the worm by itself, sending spam email messages.

An example of a Mac Mail worm discovered in 2021

Early in 2021, security researcher Mikko Kenttälä discovered a surprising Mac vulnerability within Apple's Mail app. What makes this particular worm troublesome is it requires zero clicks. It works like this:

The attacker mails a user a ZIP archive that Mail automatically unpacks under certain conditions. When unpacked, a virus file will do whatever it pleases on your computer.

How do I know if my computer has a worm?

The symptoms of worm infection vary, but the most common are the following:

  • Fans spin up for no reason.
  • Files are missing, corrupt, or locked.
  • Mac starts running slowly or erratically.
  • The hard drive or SSD space is fuller than it should be.

How to check if your Mac has been infected with a worm

If your Mac or PC has any of the symptoms listed above or you have any other reason to suspect it may have been infected, you should scan it for malware. You can do this using an antivirus program. There are several available for both Mac and PC that will allow you to download them and run a free scan. Some will also remove the worm for free, while with others, you’ll need to pay to download the full version of the software.

Using an anti-malware tool is the best way to scan your Mac for worms. I prefer CleanMyMac X because it has an immense malware database that is regularly updated. If you enable background scanning, you can be sure that no worm virus or other malware will sneak into your Mac. Here’s how to set it up:

  1. Install and launch CleanMyMac X — here is a link to a free version
  2. Go to the CleanMyMac X menu and navigate to Preferences.
  3. Select the Protection tab.
  4. Check the boxes next to "Enable Malware monitor" and "Look for threats in the background."
  5. Close Preferences.

Now, CleanMyMac X will run in the background, periodically scanning your Mac for malware, even when the app itself isn't open.

How to get rid of a worm virus on Mac

If you’re using a Mac, we advise running the Malware Removal module in CleanMyMac X to scan your Mac and remove a worm if it finds one in one click. Here’s how to utilize the tool:

  • 1. Launch CleanMyMac X.
  • 2. Choose the Malware Removal module in the sidebar.
  • 3. Press Scan.
  • 4. If CleanMyMac X finds anything, hit Remove.
Scan completed in malware removal module of CMMX

It's especially effective for detecting worms and adware scripts that hijack browser starting pages.

How to avoid getting worm malware?

There’s no way to guarantee your Mac will never be infected. Every computer connected to the internet or using external media shared with other computers is potentially at risk. However, there are several steps you can take to protect yourself.

#1. Keep your operating system and applications up to date.

Worms often exploit flaws in software to replicate themselves or spread. As soon as a worm is discovered doing this, the developer should start working on an update to fix the flaw. This will usually be available within a few days of discovery. So, by keeping your OS and applications up to date, you’re ensuring that you have the best protection against worms.

#2. Don’t click on links in emails or instant messages.

Spam messages, whether sent by email or messaging platform, are common to spread malware, worms included. They will contain a link with text that encourages you to click on it. If the malware is sent by instant message, it may tell you that it’s a video you must watch and may appear to have come from a friend. To protect yourself, don’t ever click on a link in an email or other message unless you’re certain of its origin.

#3. Be careful about what websites you visit.

Websites that offer free content that would otherwise have to be paid for, such as streaming the latest movies or distributing license codes for software, are often used to spread malware. By visiting those sites, you put your computer at risk, so they are best avoided.

Worms are a form of malware that replicate and spread quickly, often exploiting flaws in software. But you can protect yourself from them to an extent. And even if your computer is infected, you can do a great deal to get rid of the worm and restore your computer back to health.

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