What Is a Computer Worm (Worm Virus)? 

A worm virus is a type of malware that can replicate and spread from computer to computer. Worm Viruses are often used as tools for espionage or sabotage and can cause serious damage to your computer’s operating system if allowed to run unchecked.  

While viruses have been around since the 1980s, worms were first introduced in 1988 by Robert Tappan Morris, who first released “Morris worm” for academic purposes before he realised what cyber destruction the “Morris Worm” could create. 

How did The Computer Worm First Started? 

In November 1988, “The Morris worm” was launched. An estimated 6,000 – 60,000 computers connected to the internet were exploited within the first 24 hours. Modern, well-defended computers are immune to these vulnerabilities, but new generations of hackers still use worms to attack computers. They can be devastating and make thousands of people deeply suspicious of the information we store and share online.   

The Morris worm code poses no threat today; the Morris worm floppy disc is now kept at the Computer History Museum, Mountain view, CA 


Though the Morris worm was not meant to be destructive, it still caused significant damage. It took out several prominent computers and networks worldwide and was considered one of the most destructive viruses. 

Morris was the first person tried under the new Computer Fraud and Abuse Act of 1986, where he was sentenced to three years of probation, 400 hours of community service, and a fine of $10,050. Leading up to the time when this case went to appeal, DARPA created their task force, called the Computer Emergency Response Team (CERT). They coordinated information and responses to computer security throughout the trial process. 

How Does a Computer Worm Work? 

Computer worms are sophisticated malicious software programs that exploit a computer’s operating system (OS). They burrow into your computer and do their dirty work on the inside, wreaking havoc and causing data loss. These worms can also be programmed to spread to multiple devices and networks like a virus and cause more damage.  

However, today’s worms are much more likely to be delivered via email, Instant Messaging (IM) services, and networks like Dropbox instead of traditional ways. They make their way into your system through email attachments, downloads, or compromised websites. 

Once a worm infects a computer, it can use several different ways to spread itself: 

  • Emailing copies of itself to all addresses in the infected machine’s address book. 

  • Scanning for other vulnerable systems on the local network and then attacking them. 
  • Attempting to log into certain remote services such as FTP servers and mail servers with weak passwords to gain access and send copies of itself there too. 

How Does a Worm Virus Spread? 

A worm virus spreads by exploiting a vulnerability in the operating system or a security vulnerability in the network. It may also spread to other computers via email, network file sharing, or removable media. 

Computer worms spread through infected files that connect to remote systems and then transfer themselves onto those systems. The infected document looks normal until it is opened and executed on another computer (the new host). Once executed on this new host machine, the worm goes through its predetermined routines like spreading itself across networks and sending copies back to its creator/sender (called “worm-phoning home”). 

Types of Dangerous Computer Worms 

“Dangerous” is a term used by the computer industry to categorise computer worms that are damaging and disruptive. Here are list of computer worms that are considered dangerous because they can cause damage to computer systems, record private data, cause system shutdowns, and even cause system crashes. 

Email worms 

Email worms are computer viruses that can infect your computer by copying their code over to email software. This process is often done through the email client, which will send emails to everyone on your contact list. The worm will then continue its transmission by sending identical messages to those contacts and so on. 

An email with malicious links can execute and install a worm on a computer. Others contain shortened destinations in the body of the email that lead to websites hosting malware. 

If a user clicks on these links, the website may use social engineering techniques such as phishing schemes or ransomware to steal their information. For these email worms to be successful in tricking their victims into clicking on them, the links in the email usually looked very convincing. 

Instant messaging worms 

IM worms are malware that uses software to hijack your computer’s messaging platform, such as Skype, Messenger, or WhatsApp. They typically look for vulnerabilities in the software’s security systems and exploit them for their agenda. 

This message is written in a way that tries to convince your contacts that you have just sent them an important link, but it is just clickbait-esque language. 

Convinced that your friends received the message from you, they click through on a website they’re visiting, but instead of finding what they were looking for, the site provides access to unsafe data. In the meantime, their computer becomes infected and spreads the virus to all their contact list – which increases the likelihood that this virus can impact more people. 

File-sharing worms 

File-sharing worms are programs disguised as media files, such as zip files and MP3s. These worms can be found on peer-to-peer networks, torrent sites, and social media networks. They can steal sensitive information and personal data by disguising themselves as regular files. 

The Stuxnet worm is one of the most insidious pieces of malware. It consists of two components: a worm that propagates through USB devices infected with the host file and malware that targets specific industrial control systems. 

Network worms or Net-worm 

A net-worm is a type of worm that finds new host machines to infect using network shares – such as a hard drive or server. It can then access your entire company’s intranet via that one machine it just infected. 

Because many internet worms use software exploits, they can take over your computer and steal everything in just a few clicks. The worm scans a network for other computers with the same security weakness and then spreads to those machines. This allows it to quickly infect many more hosts, which can compromise security on a whole scale. 

The net-worm can only spread through a network share, which makes it difficult to prevent. To prevent the net-worm from spreading, you must ensure no computer has access to the share before the worm spreads. 

How can you protect yourself against worm virus?

In today’s cyber world, with all the cybersecurity threats out there, it’s essential to know how to protect your devices and your organisation from worm viruses. There are several ways you can do this. Here are a few tips we have listed below: 

  • Use antivirus software. Many of the more sophisticated worms can be detected by antivirus software, but it’s always a good idea to keep your computer updated to protect it from new threats. 
  • Update your operating system. You can stay one step ahead by always updating your OS and programs to the latest versions when they come out. As with antivirus software, updating your operating system will help protect you from known threats and should be done regularly. 
  • Install a firewall and make sure it’s turned on (if you don’t know what this means, ask someone who does). This is especially important if you have an Internet connection at home or work because worms use the computers they infect as “zombies” to send spam or scan the network for other vulnerable machines to infect them as well. 

  • Become a human firewall; Cyber security measures are a must for all organisations. Software and hardware firewalls, antimalware protection, and password protection are essential to prevent cyber security violations. While technical security measures are essential, they aren’t the only thing you need to worry about. A “human firewall” is a collection of practices that members of an organisation follow to maintain security. Alongside a system firewall, technical security measures are only one component of an adequate cyber security “shield”. 
  • Protect yourself by following password etiquette; By using individual passwords you are ensuring that if a virus gains access to one of your accounts (for example through emailing links or attachments from fake websites)  hackers won’t gain access to all of your accounts and personal information such as bank details. 


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Happy Eid Mubarak 1445H

Happy Eid Mubarak 1445H