Cybersecurity is a tough nut to crack because of the countless attack vectors, attack types, infiltration methods, and attack sophistication. Viruses, worms, ransomware, phishing, these are all difficult to grasp for a newcomer.
However, PrivacyAffairs is dedicated to bringing light on these issues and teaching you all about cybersecurity and cybercrime.
So, in this article, I’ll discuss the “worm”, what it is, how it behaves, attack vectors, how to spot it, and how to mitigate it.
Let’s get started!
A computer worm is a type of malware that self-replicates once it reaches the victim’s device.
Its main function is to spread from an infected device to other devices by replicating itself endlessly. It usually achieves this by exploiting the device’s OS (operating system) in subtle and invisible ways.
A worm’s key feature is that it does not need human activation or guidance to spread or self-replicate. Once it breaches a system, it’ll follow it subroutines and begin replicating and spreading throughout the network.
Worms will spread via online networks as well as physical connections (through USB) and will keep replicating in any medium they’re in.
Worms are variants of Trojan horses, so their attack vectors are varied and insidious, with most users not realizing what happens.
Here are the main ways a worm spreads across devices:
The most common computer worms spread via email. Once they’re on your device, they’ll access your email client and copies of itself to all your email contact list.
Once your contacts open your email, the worm will spread to their devices too, and keep doing this until it cannot spread anymore.
Emails containing worms that are sent by hackers will employ social engineering to manipulate you into opening the infected links or downloading the infected attachments.
Other worms will spread via instant-messaging apps like WhatsApp or Telegram. Once they’ve infected your device, the worms can access these apps and send copies of itself to all your contacts.
It’ll auto-create clickbait messages like “HEY, you HAVE to check this out” written in caps lock to attract attention and encourage them to click.
Internet worms are the most insidious, though. Hackers use them to target specific vulnerabilities in operating systems and devices. These are targeted attacks that have clear entry points and waste no resources infiltrating a device.
A computer worm will go through multiple stages once it’s released into the wild and until it reaches a device:
Stage 1 is the system entry, where the worm manages to gain access to a device either through an unsecured local network, an OS vulnerability, or through any of the other attack vectors.
Once it gains entry, a worm will begin Stage 2, which is when the real damage begins to unfold. It’s also the stage at which you have to act quickly to remove the worm from your device before it’s too late.
Once inside a device, the worm will begin Stage 2, which is replicating uncontrollably everywhere on the device where it won’t be discovered.
It will also start looking for entry points into other devices or on the local network, to see if it can infect other devices.
A worm is most dangerous once it begins replicating because it can produce a lot more damage the more numerous it is.
Stage 3 is when the worm will hide on your PC and begin attacking your device while remaining undetected for as long as possible.
In the meantime, the worm is in constant state of self-replication, spreading, and attacking your device.
Here’s exactly what a worm can do to your device:
A very common use of worms is to deliver a “payload” of code that creates a backdoor into a system. The hacker can then take control of the system or install other malware in it.
They can even turn that device into a “zombie device” that becomes part of a botnet to be used in a DDoS attack.
And it all starts from an insidious worm attack!
There are multiple types of computer worms, based on their attack vectors and infiltration methods. I’ve already mentioned some of these attack vectors.
These worm variants will create and send emails to all the contacts in your email client. They will likely include a malicious link or attachment in the email that carries a variant of itself.
The worm will likely use phishing techniques and social engineering tactics to persuade your contacts to open the infected links or attachments.
Hackers may also place a worm in an email through several methods. These include MS Outlook services, Windows MAPI functions, and inserting the worm in the text of the email.
Email worms still remain the most effective attack vector out of all worm types.
P2P file-sharing, also known as torrenting, is very dangerous from a security standpoint. It’s a preferred playground for malware, especially worms.
Hackers can disguise these worms as executable files or media files. This can mean games, movies, and especially software that you “pirate” online.
File-sharing worms are often instructed to target industrial environments like power utilities and sewage plants, if they can access them.
Cryptoworms have nothing to do with cryptocurrency. Instead, their name comes from cryptography.
These worms will encrypt the files on your system and they’re often the main element of ransomware attacks.
Hackers will encrypt and lock your files, then they will demand a ransom payment to unencrypt your files.
These worms can come from any instant message app, like Skype, WhatsApp, Telegram, Signal, and others.
They’ll take the form of attachments or links embedded into persuasive texts. Through social engineering, hackers can vary the nature of these attacks and manipulate people into clicking the malicious links or downloading the infected attachments.
Once you get the worm, it will send itself to all your social media contacts and spread onward through the network.
These worms will exploit vulnerabilities of operating systems and infiltrate whatever device they can.
Internet worms are the oldest types of worms in existence, existing since the late 20th century when the first operating systems appeared.
They will scan the internet and look for devices with known vulnerabilities. Then, once it finds one, it will infiltrate it and begin replicating.
These are all the known types of computer worms as of 2023.
These worms are relatively new because Internet-of-Things devices haven’t been around for a long time.
The Mirai worm is the most notorious of these types of worms. It infects IoT devices like smart cameras and routers and turns them into zombie devices as part of a botnet.
Once it infects an IoT device, it will look for other IoT devices on the same network or even try to access other networks through vulnerabilities.
These are all the computer worm types that are in use today. They all exploit different elements of communication and the online ecosystem to infiltrate, control, and manipulate devices.
A worm is a type of malware, but not all malware are worms. There’s a difference between different types of malware. This is what we’ll explore in this section.
The most important comparison is between a worm and a virus because they’re the most closely-related and might confuse people.
Here’s the gist of it:
So, the main difference between a virus and worm is that the worm is self-sufficient and acts autonomously without external help or interactions.
Neither the hacker nor the victim has to interact with it or activate it. Once it infects a system, it will take action immediately.
Clearly, the worm is the more dangerous one between the two. It spreads faster, takes action faster, and you have less time to mitigate a worm before it damages your device.
It’s not difficult to detect a worm infection on your device. These little buggers leave behind clear breadcrumbs that are easy to spot.
Here’s what you should be looking for:
Taken individually, none of the symptoms above might lead you to suspect a worm. But once the symptoms pile up, it becomes increasingly clear that you’re dealing with a worm.
Once you reach this stage, it’s important to remove the worm as fast as possible. Read below to see how to do that!
If you’re pretty sure you have a worm problem on your PC, here’s what you should do:
There isn’t much you can do yourself manually unless you fancy reinstalling your operating system. And that’s not something most users will prefer doing, either way.
The only thing you can do once you find a worm in your system is let your security systems deal with it.
As I always say, prevention is better than mitigation, and this is especially the case with cyberattacks that can severely impact your business if successful.
Fortunately, worms are not hard to avoid if you have surface-level knowledge and common sense when operating online.
Even if you don’t follow any of the above, at the very least, practice common sense and educate yourself about cybersecurity and cyberattacks.
You don’t need a Master’s Degree in cybersecurity or cybercrime to realize that a site looks suspicious or that an email attachment might be better left unopened.
These common-sense judgments are enough to protect you against most cyber-threats if you’re a common user.
An enterprise has no excuse not to use premium security solutions and be more aware of the risks they face online.
Computer worms are still among the most dangerous cyber-threats you can come across because of their self-replicating nature. Once a worm infiltrates your system, it’ll start spreading uncontrollably across every network connected to your device.
It’s often not easy to realize that you have a worm problem until it’s too late. Preventing it is much easier and more efficient.
Mitigation is possible but it may already be too late. It might have already deleted some files, hidden others, and created a backdoor for the hacker to exploit your system.
For more cybersecurity awareness content, keep following PrivacyAffairs!
Security Org – What Is a Computer Worm?
Eprint – IoT Goes Nuclear: Creating a ZigBee Chain Reaction
Eset – What Is a Computer Worm, and How Does It Infect a Computer?
MalwareBytes – Computer Worm
MakeUseOf – 5 Key Types of Computer Worms You Should Know
Kaspersky – What’s the Difference Between a Virus and a Worm?
WhatIsMyIP – Computer Worms and How to Prevent Them?