A Small Business Guide to Guarding Against Worm Viruses

by Patricia Staino | Published on May 18, 2022

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Worm viruses are easy to contract and spread quickly through all the computers in your network. Learn how to detect an infection and secure your devices against these threats.

You’re probably familiar with the terminology for bad things hackers do to your computer: malware, ransomware, network worm, advanced persistent threats, brute force attacks, and so many more.

It’s a challenge to keep them all straight, never mind the steps to take to protect against them. This guide explores worm viruses and lets you know how to spot them and protect your business from them.

Overview: What is a worm virus?

So, what is a worm? A worm, or worm virus, is a program that replicates itself so it can attack all devices connected to a network. A form of malware, a worm exploits vulnerabilities in security systems to gain access to your systems, then spreads from one computer to the next.

As the worm malware moves through your network, it can steal sensitive data, corrupt or delete files, or create a “backdoor” that gives a hacker remote access to your network. Sometimes, the worm program’s only purpose is to eat up hard drive space and bandwidth to overload and disrupt the network.

A worm virus is different from other computer viruses. Most often, a virus is introduced to a system as an attachment or program that needs to be opened, downloaded, or installed on a host. Then, a user will attempt to use the host, activating the virus to wreak havoc.

Worms, however, do not need any human assistance. They get to work as soon as they have been downloaded, even if a user hasn’t attempted to use a device or program.

4 types of worm malware

Unfortunately, worm malware is spread through communication means that we all use regularly. And despite warnings about clicking links and downloading files, few of us pay attention to every text and email we’re sent. Increasingly, the worm-infected communications appear legitimate, making it hard to distinguish them from messages sent by friends and colleagues.

1. Internet worms

Internet worms, or net worms, are especially vile. They infiltrate popular websites and replicate themselves on any device used to access that site, then onto any device connected to the initial infected device.

2. Email worms

These worms are distributed through -- you guessed it -- emails. The filename looks like a typical media file (such as mp4.exe), but when you click on the attachment, it sends the infected attachment to your contact list.

Because we’ve all learned we shouldn’t click on attachments from senders we don’t recognize, hackers have started embedding links in the body of the email. When you click the link, you are sent to a website that starts downloading infected files onto your computer.

3. IM worms

IM or instant messaging worms are sent through chat channels such as Messenger or WhatsApp. They’ll include links or attachments with a short message like “Check this out” or “OMG! Hilarious!” to encourage you to click the link. Like the email worm, IM worms send the infected message to the contacts on your phone or computer.

4. File-sharing worms

Because file-sharing transfers of copyrighted media files are illegal, file-sharing or peer-to-peer (P2P) worms shouldn’t be a thing. But they are. If you or your employees share copyrighted music files, for example, you have a heightened risk of exposure to a file-sharing worm.

As with IMs and emails, if you open or listen to the file, you download the worm to your computer. Often these files play the music they promise, so the user doesn’t realize the computer is now infected.

Signs your computer has a worm virus

While worms attack without warning, they don’t crawl under the radar for long. If your computer is infected, you will quickly see signs that something is wrong.

Programs that open and run automatically, erratic web browser performance, odd sounds and images, warnings from your firewall, system error messages, and emails sent to your contacts without your knowledge are all signs of a possible worm. Other major signs include the following.

Diminished hard drive space

If your computer suddenly sends messages that you’re running out of hard drive space, or you notice a big jump in the amount of space occupied when you check your storage capacity, you may be hosting a worm. As it continues to replicate, it will eat up more space on your hard drive.

Poor computer performance

If your computer is slow, programs crash, or screens freeze frequently, be on alert. Erratic performance and slow connection speeds could indicate a worm is disrupting your system performance.

Missing or unfamiliar files

If you can’t find files you know should be there, or you start seeing weird files that you didn’t create, this could be a sign that a worm is deleting files and depositing nefarious ones on your computer.

Worm security: How to protect your computer

While no worm security measures can guarantee you’ll never be infected, you should do everything you can to protect your network and computers.

1. Update software and operating systems regularly

This is one of the most crucial -- and easiest -- tips for preventing cyberattacks. The software and operating system for your computer will regularly push out updates that contain the latest security patches for threats and vulnerabilities. When these reminders pop up on your screen, accept and install them. It takes little effort on your part and immediately increases your security against new and emerging threats.

2. Beware of attachments and links in emails and texts

Admittedly, many of these attachments, links, and messages will appear legitimate, and we all make mistakes. Still, it’s worth your time to consider the validity of every email. If the name of the attachment is odd, or if it’s unsolicited, it’s best not to open it.

And if a link is embedded in the email, before clicking on it, hover over it. Double-check the site name for misspellings or lack of relevance. If you’re not absolutely sure you can trust it, don’t click.

3. Invest in endpoint security

Invest in the best endpoint security software you can afford. Endpoint security tools are essential as more workers connect from remote locations, often through personal computers, phones, and tablets. Endpoint security software will weed out suspicious emails, taking the onus off your employees.

4. Implement a zero-trust policy

Adopt a zero-trust approach to network security. This means those inside and outside your network must prove they are trustworthy, each and every time they access an application, system, or database within your network. This protects against the spread of a worm, should a computer be infected, as it will be denied access by your segmented network.

Be prepared

Worms are fast and destructive. If you suspect your computer has been attacked by one, whether through proactive threat hunting or observing the above-mentioned symptoms, disconnect from your network and the internet immediately. This will stop the worm from spreading to other computers.

Next, scan the computer with antivirus software. If it detects a worm, follow the software’s prompts to remove it. Be sure you’ve made all necessary updates to the operating system and software applications. If symptoms persist, it probably means there are other hardware issues you need to consider. At that point, asking an IT professional to evaluate the computer is your best bet.

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