Glossary of malicious software

Ransomware, Trojan horse, computer virus... In this glossary, discover the meaning of all these malicious software names, also known as "malware".

We've listed them here in alphabetical order. Some malware names are better known by their English name. We've mentioned these in brackets. For other malware names, we've kept the more common term.

3 tips to fight off malware

1. Your computer and antivirus software must be updated regularly.
2. Don't click on links that look suspicious.
3. Never reply to requests that seem suspicious.

Glossary of the most common malware

Below you'll find a description of the following software (click the term you're looking for):

• Adware
• Bot and botnet
• Trojan horse
• Spam (unwanted email)
• Cryptojacking
• Keylogger
• Zero-day exploit
• Rogue antivirus (fake antivirus)
• Form jacking
• 419 scam
• Phishing
• Spyware
• Browser hijacker
• Backdoor
• Proxy
• Computer worm
• Computer virus

Adware

Adware falls into the spyware category. It isn't the most aggressive computer virus. First, it tracks all your activity on the internet. Its aim is then to lure you to a page via advertising. This page is then used to steal your personal information, in order to resell it to an advertiser.

Bot and botnet

Bots are malicious programs that operate in an automated way, on command. A network of bots, or a "botnet", can be used to carry out large-scale cyberattacks.

Trojan horse

If you know the Iliad, you know what a Trojan horse is. In the digital world, it works the same way. It's a virus that hides inside an otherwise harmless-looking program. It can be triggered, for example, by clicking on an email attachment.

This extremely discreet piece of software can install a backdoor or a keylogger on your computer. Its goal? To let the hacker gain full access to your digital environment.

Spam (unwanted email)

This is the best-known of all "malware". In fact, spam isn't really software itself, but rather a gateway for malware. The term "spam" has entered everyday language to describe repeated, intrusive messages.

At its core, spam is an unwanted flood of advertising messages in your inbox. These promotional messages often take the form of "official" emails: a parcel is waiting for you somewhere, your loyalty card entitles you to gifts...

Today, spam is usually filtered into a specific inbox, often automatically deleted after 30 days. Be careful, though! Some emails may end up in that folder even though they aren't actually spam. It's worth checking it from time to time.

Fun fact: the word "spam" comes from "spiced ham"!

Cryptojacking

This malware simply wants to use your resources. Using software such as a Trojan horse, the hacker plants cryptojacking software on your computer. It then drains your machine's processing power to carry out electronic money laundering: cryptocurrency mining.

Your biggest risk? Noticing that your computer has become sluggish and not understanding why.

Keylogger

The keylogger falls into the spyware category. As its name suggests, it records every keystroke you make. A hacker can use this recording to discover your logins and passwords, then steal your digital identity.

Zero-Day Exploit

The term "zero-day" refers to an unknown security flaw in new software, or in a software update. This flaw may not be dangerous unless it's exploited. The term "zero-day exploit" therefore refers to a hacker using this security flaw to install a virus on your devices (computer, smartphone, tablet).

Rogue Antivirus (Fake Antivirus)

Rogue, or fake, antivirus software falls under the same category of malware as spam. It's a web page that pops up repeatedly and unexpectedly. It tells you that your computer is infected and urges you to click a link to buy an antivirus program. This is, of course, a scam.

Form Jacking

This malware doesn't affect your own devices. It's a virus that has infected an e-commerce website and is completely invisible to you and your antivirus software. It collects your banking details with the sole aim of stealing your money.

Your only recourse is with your bank. As soon as you notice suspicious withdrawals or transactions, contact your advisor to dispute them.

419 Scam

This scam is a classic email fraud. You receive a message from someone who promises you a large sum of money. To pay you this windfall, this person simply asks for your bank details.

This isn't a computer virus, since this fraud doesn't use any malware. But it's a persistent online scam that can take many forms.

Want to report this kind of email? Contact the Point de Contact, the online platform that will put you in touch with the relevant authorities in Belgium.

Phishing

Phishing is a cybercrime technique used to harvest your data. The hacker builds an email or website that looks official and legitimate. It may copy the identity of a bank, an insurer or a government body.

The goal is to get you to click and fill in your details under a fraudulent pretext. The hacker is then free to use your personal information as they please.

How can you avoid phishing?

• Look out for spelling mistakes or odd details.
• Don't click on the links in these "official" emails. If your bank or phone provider contacts you, go directly to their respective websites instead.

Careful: phishing can also happen via SMS. If in doubt, don't click!

Spyware

Spyware, like adware or keyloggers, records your habits on the web. This data is then collected by hackers who can use it for their own gain.

Ransomware

This category of malware has been booming since the 2010s. The principle is simple: the hacker locks your computer and demands a ransom to unlock it. This kind of attack can also target official institutions, businesses, or even hospitals.

If your computer is locked due to a ransom demand, don't hesitate to file a complaint with the Police right away. Giving in to the hacker's demands is not the right solution!

Browser Hijacker

A browser hijacker is a virus that takes over how your browser works (Safari, Chrome, Edge...). It can steal your identity (using spyware) as well as plant malware on your computer. It can also take control of your browsing and open ads or pages without your knowledge.

Backdoor

A backdoor is a hidden way into your computer. This access opens remotely, without you noticing. Through it, a hacker can install malware or take control of your files.

Rootkit

As its name suggests, a rootkit is planted on your computer in the same way as a Trojan horse. It's a program that hides another program. This software can lie dormant — harmless — but can also turn out to be highly aggressive in the event of an attack.

This invisibility also makes life hard for antivirus software, since it struggles to detect a hidden program.

Proxy

Strictly speaking, a proxy isn't a computer virus. It's a go-between program connecting two computers. However, it can be used for malicious purposes, such as harvesting your data. The fact that it sits outside your own environment makes it even more dangerous, since it can't be detected by your antivirus software.

Computer Worm

Unlike a computer virus, a worm is malware that spreads from computer to computer. It infects different hosts by using your local network or the internet.

Computer Virus

This is the oldest and most enduring type of malware. It attacks your computer, file by file. It's also called "self-propagating": every infected file becomes a new source of contamination.
Its impact ranges from mildly annoying to outright destructive. Protect yourself by installing a good antivirus program!

Our malware glossary isn't exhaustive! Have you come across terms you'd like explained? Feel free to leave us a comment below this article.

(Article written in collaboration with We are the Words.)

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