what are the different kinds of malware

What Are The Different Kinds Of Malware? Nasty 10!

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Last Updated on March 3, 2021 by Calvin C.

What is malware?

As you are aware, a VPN creates a tunnel in which encrypted data is exchanged between you and the VPN server. This shields you from cyber-attacks and one of those attacks is the introduction of malware into your system. In this article, we answer the question “What are the different kinds of malware?”

There is going to be serious definition of terms because most of the jargon is usually used haphazardly. By the end of this post you wil have a solid understanding of what each and every one of these malicious agents represents.

Lets start with the big one….Malware


Also called Malicious Software, this is a class of computer code that is designed to disrupt, disable or take control of your computer system. It usually comes disguised in many forms that include a harmless-looking app or file.

Malware takes advantage of security flaws in the hardware or software of your device. The majority of malware is designed to steal sensitive information, vandalize systems, cyber-espionage, hacktivism, cyber-warfare to name a few.


What are the different kinds of Malware

The following is a complete list of malware that can harm your computer or mobile device. In the next section, we look at each one of these malware in more detail:

  • Viruses
  • Worms
  • Trojans
  • Ransomware
  • Adware
  • Bots
  • Spyware
  • Fileless Malware
  • Keyloggers
  • Rootkits

1. Viruses

This is the commonest term that I’m sure you have heard of.

There are a lot of misconceptions about computer viruses and YES, your computer or mobile device can still recover from an infection by a virus.

A computer virus is a type of malware that can replicate itself and infect further computers or mobile devices.

This action occurs without the knowledge or permission of the user.

In addition, a virus can attach itself to a computer file and infect the next device where that file is saved.

For example, if you have your documents in your computer and that computer has a virus, the virus attaches itself to your files.

If you save them to a flash drive, this device becomes infected too.

Once you copy the files on your flash drive to a friend’s computer, the virus is aso transferred and further replicates to infect more files!

2. Worms

A computer worm has less destructive power than a computer virus but it habours its own undesirable effects. Like a virus, a worm has replication abilities.

This piece of malware aims to replicate from one computer to the next in a network until it takes over all the devices.

In some cases a worm changes the system settings and that cripples the whole system.

As the worm floods the whole network it uses a greater chunk of the resources like bandwidth.

Although used interchangeably, a worm and a virus are two different types of malware.

Like what has been highlighted, a computer virus spreads from one individual computer to the next.

Worms, on the other hand, target networks of computer and recruit all the devices to form a botnet.

In most cases, they use email contact lists to mount their next attack.

Another difference is that worms don’t require a host file to mount an attack like in computer viruses.

Worms are stand-alone files that do their job once they are introduced in a device.

The worst computer worm infection was by the “I Love You” worm made by a programmer from the Phillipines.

This worm infected more than 50 million computers worldwide in year 2000. The damage was estimated to exceed $5 billion dollars!

3. Trojan Horse or Trojans

A Trojan is a malware that is also a master of disguise. It can fool a Firewall and gain access to your computer.

This means the computer system is not able to separate a Trojan from a legitimate program or file.

In the end, you are able to download and install the Trojan on your computer.

Once a Trojan has gained access to your computer, it releases payloads of malware that cause havoc to your device.

In other words, a Trojan on its own is benign as it is just a vessel to act as a disguise.

However, in that vessel are all sorts of nasty malware that are ready to spread in your device once inside.

In most cases, you find Keyloggers, Adware, Spyware, Worms etc inside Trojans (more on that later)

The malware carried by a Trojan can steal passwords, banking details, financial details etc

4. Ransomware

This is another nasty malware that infects your computer or mobile device and does one of these two on your device:

  • Encrypts all the data
  • Restricts access

You are only able to access that data after you pay a stipulated sum of money. Usually you are asked to pay using a non-traceable method like Bitcoin.

One of the worst ransomware attacks happened in 2017.

Hackers released Wannacry, a ransomware that reached all corners of the world and demanded $300USD to decrypt victim’s data.

To add insult to injury, no data was released even after paying the ransom!

5. Adware and Malvertising

The is one of most common malware that you may not even be aware of. If you love downloading free software (freeware) on the internet, then you definitely encounter adware.

Adware is software that is designed to serve advertising and during the first days you could opt out.

However, adware has now evolved to be more aggressive and deceptive methods are used to force you to view the ads.

This happens by taking advantage of a flaw in the operating system of your device.

In some cases, a spyware may also be integrated in the adware, thus further compromising your privacy.

You can also be a victim of malvertising, where ads that appear on your computer are actually portals to more malware.

Examples include:

  • Pop ads with compelling call-to-action buttons
  • Banners redirecting you to dubious links

It’s easy for malvertising to make its way to legitimate sites. Big companies like Yahoo and New York Times have fallen victim to malvertising.

6. Botnet

Do you know that hackers can turn your computer into a zombie? Welcome to the world of Botnet.

If that happens, your infected computer turns into a bot or zombie and the attacker becomes the bot-master

This attack happens in a network of many computers and as a result, these infected computers can be controlled remotely by the bot-master.

Trojans, mentioned in Number 3, are responsible for the spread of botnets as they are disguised as legitimate downloads.

Once downloaded, they release worms etc that take over your device, turning it into a zombie.

Bots can be used to commit all sorts of cyber-attacks like financial fraud, distributing malware, identity theft, using your storage space.

The scary part is your computer can be part of a botnet without your knowledge.

7. Spyware

This type of malware does excatly what it says, that is, spy on your data. It gathers data on your device without your knowledge.

Then the data is sent back to an attacker who uses it for malicious intent. In most cases, this happens when you have a device that has access to the internet.

You get spyware on your computer via:

  • Trojans
  • Malvertising
  • Compromised tracking cookies

The attacker can subsequently gain access to your email activities, passwords, credit card information and other personal data.

Other effects of spyware include consumption of bandwidth resulting in a slow device or even random crashes.

8. Fileless Malware

This malware can do what other malware does traditionally e.g stealing your personal data, vandalising your operating system, without writing any files on your hard drive.

Traditional malware leaves footprints that can be detected by tools like antivirus software.

One way in which fileless malware works is by hiding in the code of a genuine computer program being run in the RAM (temporary memory).

This evolution came after anti-malware products became better at stopping cyber-attacks.

Fileless exploits are becoming more prevalent and may come in the form of:

  • Registry resident malware
  • Memory only malware
  • Fileless ransomware

We will cover these in future posts so make sure you subscribe. Only a powerful security tools can stop hackers from attacking your system with fileless malware.

9. Keyloggers

A keylogger is like a keyboard spy that watches which keys you hit and belongs to the spyware family.

It is also called a system monitor or keystroke logger and monitors each key you type on a keyboard.

This applies to any keyboard so even if you are using a virtual keyboad on your mobile device, the attack still occurs.

This type of malware is used by cyber-criminals to steal passwords, credit card details and other login credentials.

Some companies use keyloggers to monitor activities on their computers. Here they are able to detect unauthorized access to restricted content and more.

Keyloggers come as hardware-based or software-based keloggers and you are more likely to fall victim to the latter.

You can download keyloggers unintentionally and the software starts to log any actions on your keyboard. Specific anti-keylogging software is required to effectively deal with keyloggers.

10. Rootkits

The last one in the list is rootkit and this malware slips into your device stealthly. Once it is in there it takes over control of everything in your computer system.

This malware gets to the core of your computer’s operating system and once this happens there is nothing much you can do about it. The attacker can use this undetected invasion to introduce more malware to your computer.

There are many ways to get a rootkit and one of the ways is by visiting malicious sites. Once you click on call-to-action elements on the site you get attacked.

Rootkits take advantage of known vulnerabilities in applications and operating systems so by keeping your system up-to-date, you are less likely to be a victim.

It’s possible to remove rootkit from your system but it requires special software.


Now you know what the different kinds of malware are.

You can stop all this malware in its tracks by using any of the top antivirus. Go through the link below for the best deal.


Stay up-to-date on more content about cyber-security and comment below.

In the next posts we look at ways to remove or prevent malware and keep your system in optimum shape.

Tech writer and VPN expert. DIY enthusiast and loves anything to do with space science.

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