What is malware? Meaning of term explained, what to do if your device is infected and how to protect yourself

Malware is used by cybercriminals to infect devices and steal personal information

This article contains affiliate links. We may earn a small commission on items purchased through this article, but that does not affect our editorial judgement.

Watch more of our videos on Shots! 
and live on Freeview channel 276
Visit Shots! now

Google Chrome users are being warned against clicking on a pop-up which may appear when using the browser - as ignoring it could lead to people falling victim to a scam.

The pop-up issues a warning that “the site ahead contains malware." This occurs if a user is trying to click on a website that Google believes could be unsafe to visit. In a webpage about how to manage unsafe sites, Google said that this warning appears if “the site you start to visit might try to install bad software, called malware, on your computer."

Hide Ad
Hide Ad

But, what exactly is malware, what are the different types of it, how can you tell if your device is under threat from it, and what should you do if it’s already on your device? Here’s everything you need to know.

What is malware?

Malware is short for malicious software, and it is a file that infects, explores, steals or carries out any behaviour a hacker wants. It is typically delivered over a network and is targeted on people’s devices, such as computers or phones, and can affect anything with computing or programming capabilities. It is also designed to cause damage to the device, or disrupt its typical use, and is a method attackers use to gain unauthorised access to people’s private information.

What are the different types of malware?

Malware has been around for more than 30 years. The first example of malware was a computer virus, but there are now several methods of attack for cybercriminals. According to McAfee antivirus software, they include email attachments, malicious advertisements which are called malvertising, fake software installations, infected USB drives, infected apps, phishing emails and fake text messages. There are also different types of malware that can be used.

The eight different types of malware, and how scammers and hackers get them on to people’s devices, are described below:


Hide Ad
Hide Ad

A virus usually comes as an attachment in an email. Once the victim opens the file, the device is infected.


Ransome is very profitable for scammers and is therefore very popular. This is a file which instals itself onto a victim’s machine, encrypts their files, and then a payment - or ransom - is demanded from the criminal so that they can get their data back. Often, criminals will ask for Bitcoin as ransom payment.


This is where scammers convince people that their device has already become compromised, and then convince them to buy a fake application which will supposedly fix the bogus issue. In fact, it is the application itself that will infect their device. In a typical scareware scam, you might see a message while browsing the internet that states “warning: your computer is infected” or “you have a virus”. Cybercriminals use these unethical advertising practices to scare users into buying and downloading rogue applications.


Worms have the ability to copy themselves from machine to machine, usually by exploiting a security weakness in a software or operating system. The key thing with these worms is that they don’t require user interaction to function, so they can go undetected.

8 types of malware to be aware of, plus how to protect your devices from attacks.8 types of malware to be aware of, plus how to protect your devices from attacks.
8 types of malware to be aware of, plus how to protect your devices from attacks.


Hide Ad
Hide Ad

Spyware is a program installed on a person’s computer, usually without their knowledge, which sees, records and transmits their personal information or Internet browsing habits. Using spyware, criminals can monitor all communication from the targeted device.


Trojans appear to be harmless applications which trick users into downloading and using them. They are used to steal personal data, crash a device or spy on activities.


Adware programs show unwanted advertisements to users, such as pop-up windows, when people perform a certain action on their device. Adware programs are often installed in exchange for another service, such as the right to use a program without paying for it

Fileless malware

Fileless malware uses legitimate programs to infect a computer, and as a result they leave no malware files to scan and no malicious processes to detect. This means they are very difficult to detect and remove.

How do I know if my computer has been infected by malware?

Hide Ad
Hide Ad

There are several ways that people can tell that their device has been infected by malware. They are:

  • A slow-performing device
  • A device that frequently crashes
  • Frequent pop-up advertisements
  • Issues when loading or shutting down a device
  • Infection warnings, often accompanied by an application download to ‘fix’ the issue
  • Being redirected to internet sites you have not searched for
  • Being unable to remove applications or software from your device
  • Emails are sent to contacts which you didn’t write
  • A device that runs out of battery quicker than usual

How can I protect myself against malware?

The best way to protect yourself from malware is to be careful what you do with your devices. For example, only download apps and software which you know you can trust. Look for apps, for example, which have been verified and have many other user reviews. If you do get any pop-ups or suspicious advertising on your device, do not click on any links included and instead click on the cross button to get rid of them. If you visit a website that asks you to download anything onto your device or suddenly presents lots of pop-ups then navigate away from that site. In addition, avoid websites that offer services for free which you would usually have to pay for, such as free films, because these offers often are too good to be true and could have malware linked to them. Use your common sense too; if you get an email with a link, for example, that doesn’t look quite right or you weren’t expecting it then don’t click on it.

You can also download antivirus software, security software and malwarebytes, which is an anti-malware software for Microsoft Windows, macOS, ChromeOS, Android, and iOS that finds and removes malware. These help prevent the malware being downloaded onto your device in the first place, and you can also perform regular checks on your device to ensure that they are malware free. It’s important to ensure that such software is up-to-date so they will work effectively.

Comment Guidelines

National World encourages reader discussion on our stories. User feedback, insights and back-and-forth exchanges add a rich layer of context to reporting. Please review our Community Guidelines before commenting.