What Is Malware?

Date First Published: 3rd May 2023

Topic: Cybersecurity

Subtopic: Threats To Systems, Data & Information

Computer Terms & Definitions

Difficulty: Easy

Difficulty Level: 3/10

CONTENTS

Types Of Malware
Detection

Learn more about what malware is in this article.

Malware is a general term for any type of software specifically designed to harm a computer system. It is created with malicious intent to steal data, gain unauthorised access, disrupt a computer system, server, or computer network, or cause other issues.

Malware spreads through internet downloads, flash drives, and peer-to-peer programs and is often installed through deceptive techniques. For example, you might get a site claiming to offer a useful utility for your computer, when it is actually a malicious program that logs keystrokes and steals your sensitive information from your web browser. It can also be spread through vulnerabilities in web browsers and operating systems.

Types Of Malware

Below are examples of different types of malware:

Virus - A self-replicating type of malware that copies itself in order to infect other devices. The terms 'malware' and 'virus' are often used synonymously, but a virus is just one type of malware.
Trojan horse - A type of malware that disguises itself as a safe and legitimate program when it actually performs malicious tasks in order to trick users into opening and running it. Trojan horses appear to be something useful and harmless, when they are actually something malicious.
Spyware - A type of malware that is designed to secretly monitor the victim's activity, gather information about them, and send it to a third party without their permission. Spyware often steals sensitive information, like passwords and bank details.
Ransomware - A type of malware that blocks access to a computer system or files until a sum of money is paid. Ransomware may encrypt the victim's personal files so that they are inaccessible or lock the victim out of their computer for a ransom.
Backdoor - A type of malware that is designed to gain remote access to the victim's computer and secretly establish a backdoor without their permission.
Adware - A type of malware designed to display unwanted ads and popups to generate revenue for the developer. Adware often tracks a user's browsing history to target ads towards them.
Keylogger - A type of malware that records all keystrokes a user makes and sends that data to a third party. Keyloggers can record sensitive information, like passwords and bank details. They are a type of spyware.
Worm - A self-replicating malware that spreads over a network without any interaction from the creators.
Rootkit - A type of malware designed to give someone root or administrator-level access to a computer system without permission. Rootkits are designed to be difficult to spot and remove.

Detection

The best way to detect malware is by using an up to date and reputable antivirus program. Antivirus programs are designed to detect and remove malware and other unwanted programs that harm a computer. They detect malware using stored virus signatures, and based on heuristics and behaviour. They also provide real-time protection against malware which scans recently created and opened files in the background. If any malware is detected, the antivirus will usually display a message asking the user if they want to quarantine, remove, or keep it.

Current versions of Windows and Mac come with a built-in antivirus, so there is often no need to install a third-party antivirus. However, if you do decide to install a third-party antivirus, be very careful where you install it from as there are lots of fake antiviruses that trick you into thinking that something is malicious when it isn't, which could cause you to lose important files. Some antiviruses may actually be viruses themselves.

Some types of malware try to prevent themselves from being detected by antiviruses by using technical measures. Encrypting the malware payload so that antiviruses cannot recognise the signature and changing its form into variants so that the signatures vary enough to prevent detection are examples of ways that malware detection is prevented. Therefore, it is impossible for an antivirus to be 100% accurate and detect every type of known malware.