13 Types of Malware You Need To Know In 2025

In 2025, being aware of the various types of malware is more crucial than ever.

The threats are evolving, and we need to stay one step ahead.

Let's dive into the essential types of malware that you really need to know.

‍

What is malware?

Malware, short for "malicious software," is sneaky software designed to cause harm.

It encompasses a wide range of harmful programmes designed to:

• Infiltrate and damage computers or networks
• Steal your information
• Damage your files
• Hijack your computer
• and more...

As technology advances, so do the tactics employed by cybercriminals, making it imperative for individuals and organisations alike to remain vigilant and informed.

Moreover, the impact of malware extends beyond mere inconvenience; it can lead to significant financial losses, data breaches, and even reputational damage for businesses.

In an era where remote working is increasingly common, the potential for malware to exploit vulnerabilities in home networks and personal devices has surged.

Consequently, understanding the landscape of malware is not just about recognising the threats but also about adopting proactive measures to defend against it.

Now, malware takes many forms.

Each type has its own methods and dangers.

Knowing what they look like helps keep you safe from these digital threats.

So let's dive in and start unpacking the different types of malware and look at how you can defend against it.

‍

Understanding the Different Types of Malware

Now, let's explore the different types of malware you might encounter. Here are 13 types you need to be aware of in 2025.

‍

#1 Ransomware

‍

What is Ransomware?

Imagine this: you turn on your computer, and all your files are suddenly locked.

Photos, documents—everything you need—gone.

A message pops up, demanding money to get them back.

That’s ransomware.

Ransomware is a type of software that takes your data hostage.

It sneaks into your system, uses encryption to disable access to your data and demands money to release them.

Scary, right?

Ransomware can cause a lot of damage, and it’s crucial to know how it works so you can protect yourself.

Key things to remember:

• It locks your files and demands money.
• It spreads through phishing emails or bad downloads.
• Paying doesn’t guarantee you’ll get your data back.
• It can shut down businesses for days or even longer.
• Preventing it is cheaper and easier than dealing with the aftermath.

‍

How Does Ransomware Work?

It usually starts with one wrong click — a suspicious link in an email or a sketchy attachment.

Once inside, it silently takes control of your system.

It encrypts your files, and suddenly, you’re locked out.

Next, a ransom note appears, demanding money to unlock your files.

They may even threaten to delete or leak your data if you don’t pay fast enough.

It’s a stressful moment, and paying them is risky — there’s no guarantee they’ll keep their word.

Remember these key points:

• Ransomware often spreads through phishing emails.
• It locks your files so you can’t use them.
• A ransom note demands payment, usually with a tight deadline.
• Paying doesn’t guarantee you’ll get your data back.
• Backups are your best defense.

‍

Examples of Ransomware

Ransomware comes in different forms, but they all want the same thing — your money.

Here are some well-known examples:

• WannaCry: A global attack in 2017, impacting hundreds of thousands.
• Ryuk: Targets businesses, demanding big payouts.
• LockBit: Well-organized, often targets companies with weak defenses.
• Maze: Locks data and threatens to leak it.
• Petya: Shuts down your entire system until you pay.

‍

#2 Fileless Malware

‍

What is Fileless Malware?

Imagine this: you’re working on your computer, and everything seems fine.

But in the background, something dangerous is happening, and you don’t even notice.

That’s fileless malware.

Unlike traditional malware, it doesn’t rely on files you can see.

Instead, it injects malicious code in your computer’s memory, making it harder to detect.

Fileless malware uses tools that are already on your computer, like PowerShell, to do its damage.

It doesn’t leave obvious traces, which makes it tricky for antivirus programs to catch.

It’s like an invisible intruder using your own tools against you.

Here’s what you need to know:

• Fileless malware doesn’t use traditional files, making it hard to detect.
• It uses legitimate system tools to carry out attacks.
• It’s often delivered through phishing emails or compromised websites.
• Traditional antivirus programs struggle to find it.
• Prevention requires strong system monitoring and updated defenses.

‍

How Does Fileless Malware Work?

It usually starts with an email or a compromised website.

You click a link, and without realizing it, the malware enters your system.

Instead of installing a file, it uses tools already on your computer, like scripts or macros, to carry out its attack.

Since it doesn’t leave files behind, it’s much harder to spot.

Once in, fileless malware can steal your data, spy on your activities, or even take full control of your system.

Because it blends in with normal processes, it’s easy to miss until it’s too late.

Keep these key points in mind:

• Fileless malware often spreads through phishing or bad websites.
• It uses your own system tools to avoid detection.
• It doesn’t leave obvious files, making it hard to track.
• It can steal data or control your system without you knowing.
• Monitoring system activity is key to catching it early.

‍

Examples of Fileless Malware

Fileless malware is sneaky, but there are some well-known types that have caused a lot of trouble.

Here are some key examples:

• PowerShell-based Attacks: Use PowerShell scripts to execute harmful actions.
• Emotet: Evolved from banking malware to a fileless threat.
• Kovter: Hides in memory and uses registry keys to avoid detection.
• Poweliks: Uses legitimate processes to stay hidden.
• SamSam: Combines ransomware with fileless techniques, making it very dangerous.

‍

#3 Spyware

‍

What is Spyware?

Imagine someone watching everything you do on your computer.

Tracking every website you visit, every password you type, and even reading your emails.

That’s what spyware does. It’s a type of malware that hides on your device and collects your personal information without you knowing.

Spyware can be used for many reasons — advertisers might use it to learn about your habits, while criminals could use it to steal your identity.

It’s like having someone peeking over your shoulder all the time, and you might not even know they’re there.

Here’s what you need to know:

• Spyware secretly monitors your activities and collects data.
• It often gets installed through malicious downloads or fake software updates.
• It can steal sensitive information like passwords and credit card numbers.
• Spyware can slow down your computer and invade your privacy.
• Removing it can be tricky without the right tools.

‍

How Does Spyware Work?

Spyware often sneaks onto your computer when you click on a fake link or download something from an untrusted source.

Once it’s in, it hides in the background, quietly watching what you do.

It can log your keystrokes, track the sites you visit, and even take screenshots of your activity.

The scary part is that it’s designed to stay hidden.

You might notice your computer running slower or some strange ads popping up, but many people don’t realize they have spyware until their information has already been stolen.

Keep these key points in mind:

• Spyware usually gets in through fake links or untrusted downloads.
• It runs quietly in the background, tracking everything you do.
• It can steal sensitive information like passwords and personal data.
• You might notice a slower computer or strange ads, but it often goes unnoticed.
• Regular scans and careful browsing can help protect you.

‍

Examples of Spyware

There are many types of spyware, each with its own tricks.

Here are some key examples:

• Keyloggers: Record your keystrokes to steal passwords and personal info.
• Adware: Tracks your browsing habits to serve you targeted ads.
• Trojan Spyware: Disguises itself as safe software to steal your data.
• FinSpy: Used for surveillance, often by those targeting individuals.
• CoolWebSearch: Redirects your browser and collects information without permission.

‍

#4 Adware

‍

What is Adware?

Imagine you’re browsing the web, and suddenly, ads start popping up everywhere.

They follow you from page to page, showing you things you never asked for.

That’s adware.

It’s a type of malware that floods your device with unwanted ads to make money for its creators.

Adware isn’t just annoying — it can also track your browsing habits.

It watches where you go online and what you click on, building a profile to serve you more ads.

It’s like having someone looking over your shoulder, figuring out what you like so they can sell to you.

And it can slow your computer down, making it frustrating to use.

Here’s what you need to know:

• Adware shows you unwanted ads to make money for its creators.
• It tracks your browsing habits to show more targeted ads.
• It often gets onto your computer through free software or fake downloads.
• It can slow down your computer and be hard to remove.
• Good antivirus software can help keep it away.

‍

How Does Adware Work?

Adware usually sneaks onto your device bundled with free software or through fake downloads.

Once it’s in, it starts bombarding you with ads.

Sometimes they pop up on your screen, and other times they change your browser settings to show you ads on the sites you visit.

The goal is simple: make money by getting you to click.

It tracks what you do online to show ads that are more likely to get your attention.

It’s not just annoying—it can also compromise your privacy and make your computer slower.

Keep these key points in mind:

• Adware often comes bundled with free software or fake downloads.
• It floods your device with ads, sometimes even changing your browser settings.
• It tracks what you do online to serve targeted ads.
• It can slow down your computer and make browsing frustrating.
• Avoiding suspicious downloads and using good antivirus software can help.

‍

Examples of Adware

There are many kinds of adware, each trying to make money by showing you ads.

Here are some key examples:

• Fireball: Takes over your browser and floods it with ads.
• Appearch: Redirects your searches to show ads instead of real results.
• Gator: One of the first adware programs, tracking users to serve ads.
• DollarRevenue: Bundles with free software to generate pop-up ads.
• DeskAd: Adds toolbars and changes settings to push ads on your browser.

‍

#5 Trojan

‍

What is a Trojan?

Imagine downloading what looks like a useful program, only to find out it’s hiding something harmful inside.

That’s a Trojan.

Named after the famous Trojan Horse, it’s a type of malware that disguises itself as something safe.

Once you let it in, it can do serious damage to your computer or steal your information.

Trojans trick you into thinking they’re helpful.

They often come in the form of software, games, or even email attachments.

Once they’re inside, they can open a backdoor for hackers, steal your data, or even take control of your device.

It’s like inviting a thief into your home without realizing it.

Here’s what you need to know:

• Trojans disguise themselves as legitimate files or programs.
• They often come through email attachments, fake downloads, or pirated software.
• Once inside, they can steal data, spy on you, or open a backdoor for hackers.
• They rely on you to let them in, unlike viruses that spread on their own.
• Good antivirus software and cautious downloading can help keep them out.

‍

How Do Trojans Work?

Trojans usually need you to make the first move.

You might download what you think is a useful app or click on a convincing email attachment.

Once you do, the Trojan installs itself and starts working quietly in the background.

It might create a backdoor, letting hackers access your device, or it could steal sensitive information like passwords and banking details.

The worst part? Trojans can do all this without you noticing until it’s too late.

They don’t replicate like viruses but rely on tricking you into opening the door for them.

Keep these key points in mind:

• Trojans need you to download or open something to get in.
• They can steal your information or give hackers access to your computer.
• They work in the background, often without any obvious signs.
• They don’t spread by themselves—they rely on tricking you.
• Careful downloading and good antivirus software are your best defenses.

‍

Examples of Trojans

Trojans come in many forms, each with a different goal.

Here are some key examples:

• Emotet: Originally a banking Trojan, stealing sensitive data.
• Zeus: Targets financial information, often stealing banking details.
• NanoCore: A Remote Access Trojan (RAT) that lets hackers control your device.
• FakeAV: Pretends to be antivirus software, then demands money.
• Trojan.Dropper: Used to install more malware once it’s inside.

‍

#6 Worms

‍

What is a Worm?

Picture a virus that doesn’t need you to do anything to spread.

It just moves on its own, jumping from computer to computer, causing damage along the way.

That’s a worm.

Unlike Trojans, worms don’t need you to download or click anything — they spread automatically, often through networks or by exploiting vulnerabilities.

Worms can replicate themselves endlessly, making them especially dangerous.

They can spread quickly across networks, infecting every connected device.

It’s like having a contagious disease in a crowded room—once one computer is infected, the worm moves on to the next without needing any help.

Here’s what you need to know:

• Worms spread on their own, without user action.
• They often exploit network vulnerabilities or weak security.
• They can cause widespread damage by clogging up networks or deleting files.
• Worms replicate themselves, making them harder to contain.
• Keeping software updated and using a good firewall can help prevent them.

‍

How Do Worms Work?

Worms are self-sufficient.

They find weaknesses in systems or networks, and once they get in, they start spreading automatically.

They often use email, instant messaging, or network vulnerabilities to move from one device to another.

Unlike Trojans, they don’t need you to do anything—they’re on the move as soon as they find a way in.

Once inside, worms can do different kinds of damage.

Some simply spread, using up system resources and slowing everything down.

Others might delete files, steal data, or create backdoors for hackers to exploit.

And because they move so fast, they can infect thousands of computers in no time.

Keep these key points in mind:

• Worms spread by themselves, often through networks or emails.
• They exploit weak security to move from device to device.
• Once inside, they can slow down systems, steal data, or delete files.
• They don’t need user action to spread—just a vulnerability.
• Regular updates and strong network security are key to stopping them.

‍

Examples of Worms

There have been some infamous worms over the years.

Here are some key examples:

• ILOVEYOU: Spread through email, causing massive damage worldwide.
• Code Red: Targeted Windows servers, spreading quickly across networks.
• Sasser: Exploited Windows vulnerabilities, spreading automatically.
• Conficker: Infected millions by exploiting Windows flaws.
• Stuxnet: Targeted industrial systems, showing the power of worms in specific attacks.

‍

#7 Exploit Kits

‍

What is an Exploit Kit?

Imagine visiting a website, and without you doing anything, your computer gets infected.

That’s what exploit kits do.

They’re tools used by hackers to find and exploit weaknesses in your system, often through a simple visit to an infected webpage.

They’re like burglars who already know which window is unlocked and how to get in without making a sound.

Exploit kits look for vulnerabilities in software — like your browser or plugins — that haven’t been updated.

Once they find a weakness, they launch malware onto your computer, all without you even realizing.

It’s fast, stealthy, and dangerous.

Here’s what you need to know:

• Exploit kits look for unpatched software vulnerabilities.
• They often work through compromised websites or ads.
• They deliver malware without the user having to click or download anything.
• Keeping software updated is the best defence against them.
• They’re used to install a variety of malware, from ransomware to spyware.

‍

How Do Exploit Kits Work?

Exploit kits often start with a compromised website.

You visit a site that looks normal, but in the background, it’s scanning your computer for weaknesses.

If it finds an outdated plugin or software with a known flaw, it strikes.

The exploit kit then launches malware onto your system—this could be anything from ransomware to spyware.

The trick is that you don’t need to do anything.

Just visiting the site is enough.

These kits are automated, making them efficient tools for hackers who want to reach as many victims as possible with minimal effort.

Keep these key points in mind:

• Exploit kits often target users through compromised or malicious websites.
• They look for weaknesses in software, like outdated browsers or plugins.
• Once they find a vulnerability, they install malware without any user action.
• They’re highly automated, making them effective for widespread attacks.
• Regularly updating software and using a secure browser can help protect you.

‍

Examples of Exploit Kits

There have been several well-known exploit kits that have caused significant damage.

Here are some key examples:

• Angler: Known for exploiting many vulnerabilities and delivering various types of malware.
• Nuclear: Targeted users through malicious ads and compromised websites.
• RIG: Still active, often spreading ransomware by exploiting outdated software.
• Neutrino: Delivered ransomware and banking Trojans before going offline.
• Blackhole: One of the first major exploit kits, widely used before being taken down.

‍

#8 Rootkits

‍

What is a Rootkit?

Imagine a piece of malware that hides so well, you don’t even know it’s there.

That’s a rootkit.

It’s a type of software that gives hackers control of your computer while staying completely hidden.

Rootkits are designed to avoid detection, making them one of the most dangerous forms of malware.

Rootkits can be used to steal your data, monitor your activity, or even control your entire system.

They operate deep within your computer, often at the system or kernel level, which means they can hide from most security tools.

It’s like having an invisible intruder in your house, able to watch and manipulate everything without you knowing.

Here’s what you need to know:

• Rootkits hide deep in your system, making them hard to detect.
• They give hackers control over your device.
• They can steal data, spy on you, or make changes to your system.
• Often installed through phishing attacks or by exploiting software vulnerabilities.
• Specialized tools are needed to find and remove them.

‍

How Do Rootkits Work?

Rootkits work by embedding themselves deep in your computer, often at the system level.

They usually get in through phishing emails, malicious downloads, or by exploiting vulnerabilities in your software.

Once installed, they give attackers complete control over your system, all while staying hidden from regular antivirus software.

Rootkits can change system settings, install other malware, or even watch everything you do.

The scariest part is that they’re almost impossible to detect without special tools.

They hide from antivirus programs, making it easy for hackers to stay in control for a long time.

Keep these key points in mind:

• Rootkits often get in through phishing emails or malicious downloads.
• They embed themselves deep in your system, making detection very difficult.
• Once installed, they give hackers full control over your computer.
• They can change settings, install more malware, or spy on you.
• Specialized tools are needed to detect and remove rootkits.

‍

Examples of Rootkits

There have been some notorious rootkits over the years.

Here are some key examples:

• Sony BMG: Installed a rootkit to prevent piracy, which led to privacy concerns.
• Zeus: A rootkit used to steal banking information while staying hidden.
• Stuxnet: Targeted industrial systems with a highly sophisticated attack.
• TDL-4: Known for its advanced hiding techniques, making it very hard to detect.
• Necurs: Used to spread other malware, staying hidden for long periods.

‍

#9 Keyloggers

‍

What is a Keylogger?

Imagine someone recording every keystroke you make on your computer — every password, every message, every search.

That’s what a keylogger does.

It’s a type of malware that tracks everything you type, often without you even knowing it’s there.

Keyloggers are used by attackers to steal sensitive information like usernames, passwords, and credit card numbers.

Keyloggers can be installed in many ways:

1. phishing emails,
2. malicious downloads, or
3. exploiting vulnerabilities in your system

Once installed, they start recording your keystrokes and send the data back to the attacker. It’s like having someone standing behind you, watching everything you type.

Here’s what you need to know:

• Keyloggers record every keystroke you make, capturing sensitive information.
• They often get installed through phishing emails or malicious downloads.
• They can steal usernames, passwords, credit card details, and other private information.
• Keyloggers are often used for identity theft and fraud.
• Good antivirus software and caution when clicking links can help prevent them.

‍

How Do Keyloggers Work?

Keyloggers work by silently running in the background of your computer.

They capture every keystroke you make, from login credentials to personal messages.

Most keyloggers are delivered through phishing emails, fake software updates, or malicious downloads.

Once installed, they begin recording and sending your data to the attacker.

The danger is that keyloggers are incredibly hard to notice.

There are usually no obvious signs that one is running, which means attackers can collect a lot of personal information before you even know something is wrong.

Keep these key points in mind:

• Keyloggers often enter through phishing emails or fake downloads.
• They run quietly in the background, recording every keystroke.
• They can steal sensitive information like passwords and credit card numbers.
• There are often no visible signs of a keylogger on your system.
• Regular scans and cautious browsing habits can help protect you.

‍

Examples of Keyloggers

There have been many types of keyloggers over the years, each with a different approach to stealing information.

Here are some key examples:

• Spyrix: Often used for monitoring but can be misused for malicious purposes.
• KidLogger: Marketed for parental control but sometimes used without consent.
• Ardamax: Popular with cybercriminals for stealing personal information.
• Revealer Keylogger: Used to track keystrokes on personal computers.
• HawkEye: An advanced keylogger used in targeted attacks to steal business data.

‍

‍

#10 Bots and Botnets

‍

What is a Botnet?

Imagine your computer being taken over and used as part of a massive army of devices — all without you even knowing.

That’s what happens in a botnet.

A botnet is a network of infected devices controlled by hackers.

They use these devices, or "bots," to carry out large-scale attacks, send spam, or spread malware, all while you remain unaware.

Botnets are often created by infecting devices with malware.

Once a device is part of a botnet, it follows commands from a central server.

It could be used in a DDoS attack, overwhelming a website with traffic, or to send out millions of spam emails.

It’s like your computer being hijacked and used in a criminal operation without you realizing it.

Here’s what you need to know:

• Botnets are networks of infected devices controlled by hackers.
• They can be used for DDoS attacks, spamming, or spreading malware.
• Devices are often infected through phishing, malicious downloads, or vulnerabilities.
• You might not even know your device is part of a botnet.
• Strong antivirus software and keeping your system updated can help prevent infection.

‍

How Do Botnets Work?

Botnets start with malware.

Hackers infect computers or other devices through phishing emails, fake downloads, or by exploiting vulnerabilities.

Once the malware is installed, the device becomes part of the botnet and starts following commands from the botnet controller.

These commands can include attacking websites, sending spam, or distributing malware to other devices.

The real danger of botnets is in their numbers.

A single computer might not be powerful, but thousands or millions of infected devices working together can do serious damage.

And the worst part? Most users don’t even realize their device is involved.

Keep these key points in mind:

• Botnets are created by infecting devices with malware.
• Infected devices are controlled remotely by hackers.
• They’re often used in DDoS attacks or to spread spam and malware.
• Most people don’t realize their device is part of a botnet.
• Regular updates and strong antivirus protection can help keep your device safe.

‍

Examples of Botnets

There have been some major botnets over the years, each capable of causing significant disruption.

Some examples include:

• Mirai: Targeted IoT devices and launched massive DDoS attacks.
• GameOver Zeus: Used to steal banking information and perform DDoS attacks.
• Conficker: Spread by exploiting Windows vulnerabilities, infecting millions.
• Storm Botnet: Sent out millions of spam emails.
• Cutwail: Focused on spamming and spreading other malware.

‍

#11 Mobile Malware

‍

What is Mobile Malware?

Imagine your phone, the device you use every day for everything — from messaging friends to managing your bank accounts — suddenly being compromised.

That’s what mobile malware does.

It’s a type of malicious software designed specifically to target smartphones and tablets.

Mobile malware can steal your data, track your location, or even take over your entire device.

Mobile malware often sneaks in through apps.

It could be a fake version of a popular app or something that looks harmless.

Once installed, it can start collecting personal information, sending messages without your permission, or tracking your activity. It’s like having a spy in your pocket that you never even noticed.

Here’s what you need to know:

• Mobile malware targets smartphones and tablets.
• It often spreads through malicious apps or fake downloads.
• It can steal personal data, track your location, or take control of your device.
• Some mobile malware can even run up charges by sending premium-rate messages.
• Downloading apps only from trusted sources and keeping your device updated can help prevent infection.

‍

How Does Mobile Malware Work?

Mobile malware usually gets onto your device through apps.

You might download what looks like a game or a utility app, but in reality, it’s malicious software.

Once installed, it can steal your contacts, track your location, or even take control of your phone.

Some mobile malware can even send premium-rate text messages, costing you money without you knowing.

Many times, mobile malware works quietly in the background, so you don’t even realize it’s there.

It can disguise itself to look like a legitimate app, making it harder to spot.

That’s why it’s so important to be careful about what you install.

Keep these key points in mind:

• Mobile malware often spreads through fake or malicious apps.
• It can steal data, track your location, or take control of your phone.
• Some types can send premium-rate messages, costing you money.
• It often runs quietly in the background, making it hard to detect.
• Only download apps from trusted sources and keep your phone’s software up to date.

‍

Examples of Mobile Malware

There have been several well-known types of mobile malware that have caused trouble for users.

Examples include:

• HummingBad: Infected millions of Android devices to generate fraudulent ad clicks.
• Triada: Gained deep access to Android systems, making it tough to remove.
• Judy: Used apps on Google Play to generate fake ad clicks.
• Pegasus: Spyware capable of tracking calls, messages, and activating the camera.
• WireX: Turned devices into part of a botnet for DDoS attacks.

‍

#12 Wiper Malware

‍

What is Wiper Malware?

Imagine all the files on your computer being completely erased, with no way to get them back.

That’s what wiper malware does.

It’s a type of malware designed to delete or destroy data on a targeted device, often leaving it completely unusable.

Unlike ransomware, which holds your files hostage, wiper malware’s goal is pure destruction.

Wiper malware can hit businesses, individuals, or even government systems, causing massive damage.

It doesn’t ask for a ransom or steal data—it simply wipes everything it can.

It’s like having a malicious intruder break into your home and destroy all your belongings, leaving nothing behind.

Here’s what you need to know:

• Wiper malware is designed to destroy data, not steal it.
• It often spreads through phishing emails or exploits vulnerabilities.
• It can leave devices completely unusable.
• Unlike ransomware, there’s no chance of recovery by paying a ransom.
• Backing up your data regularly is the best defense against wiper malware.

‍

How Does Wiper Malware Work?

Wiper malware usually starts with a phishing email or by exploiting a security vulnerability.

Once it gets into a system, it spreads quickly, targeting important files and system components.

It overwrites or deletes files, making recovery nearly impossible.

Sometimes, it will even corrupt the system’s boot process, preventing the device from starting up at all.

The goal of wiper malware is to cause as much damage as possible.

Unlike other types of malware that might try to stay hidden, wipers are loud and destructive.

Once they’ve done their job, there’s often no way to recover what was lost.

Keep these key points in mind:

• Wiper malware often enters through phishing emails or security vulnerabilities.
• It targets important files and system components, deleting or corrupting them.
• It can prevent devices from starting up, making them useless.
• Its goal is destruction, not ransom or data theft.
• Regular backups are crucial to protect against wiper malware.

‍

Examples of Wiper Malware

There have been several high-profile cases of wiper malware causing widespread damage, including:

• Shamoon: Targeted energy companies, deleting data and crippling operations.
• NotPetya: Looked like ransomware but had no way to recover data, causing major disruptions.
• StoneDrill: Used advanced techniques to target government and private sectors.
• Olympic Destroyer: Disrupted the 2018 Winter Olympics by deleting data.
• Destover: Linked to attacks on corporations, causing significant data loss.

‍

#13 Cryptojacking

‍

What is Cryptojacking?

Imagine your computer suddenly running slower, the fan spinning like crazy, and your battery draining faster than usual.

You might be a victim of cryptojacking.

Cryptojacking is a type of malware that secretly uses your computer’s processing power to mine cryptocurrency.

Instead of stealing your data, it steals your computer’s resources, making money for the attacker while you suffer the slowdown.

Cryptojacking often happens when you click on a malicious link or visit an infected website.

Without you even noticing, a piece of code starts running on your device, using its power to mine cryptocurrency.

It’s like someone sneaking into your house and plugging in their equipment, running up your electric bill while they profit.

Here’s what you need to know:

• Cryptojacking secretly uses your device to mine cryptocurrency.
• It often spreads through malicious links, infected websites, or compromised apps.
• It doesn’t steal your data, but it uses your computer’s power, slowing it down.
• You might notice your device running hot, slower, or draining battery quickly.
• Good antivirus software and browser extensions can help block cryptojacking scripts.

‍

How Does Cryptojacking Work?

Cryptojacking usually starts with a click.

You might click on a link in a phishing email or visit a compromised website, and without realizing it, a cryptomining script starts running on your device.

This script uses your computer’s resources — its CPU or GPU — to solve complex mathematical problems that generate cryptocurrency for the attacker.

The problem is that these scripts use up a lot of processing power, which can make your device slow and unresponsive.

You might notice your computer getting hot, your fan running constantly, or your battery draining faster than normal.

All of this happens while the attacker is making money, and you’re left dealing with the performance issues.

Keep these key points in mind:

• Cryptojacking often starts with a click on a phishing link or visiting a compromised website.
• It uses your computer’s CPU or GPU to mine cryptocurrency.
• It can cause your device to run hot, slow down, or drain battery quickly.
• Unlike other malware, it doesn’t try to steal your data—it just uses your resources.
• Browser extensions and antivirus tools can help prevent cryptojacking.

‍

Examples of Cryptojacking

There have been several notable examples of cryptojacking attacks.#.

Here are some key examples:

• Coinhive: A widely used script that mined Monero without user consent.
• Smominru: A large botnet that infected thousands of devices to mine cryptocurrency.
• BadShell: Used built-in Windows tools to mine cryptocurrency, avoiding detection.
• Digmine: Spread through messaging apps, using victims’ devices for cryptomining.
• PowerGhost: Targeted businesses, affecting productivity by running mining scripts on corporate networks.

‍

How Does Malware Spread?

Understanding how malware spreads can help you stay safe.

It often comes through malicious email attachments, downloads, and links.

Being cautious with what you click on is vital.

Social engineering is another tactic hackers use.

They trick you into giving away sensitive information or clicking on a malicious link. Always double-check before taking action!

Public Wi-Fi networks can also be risky.

Avoid accessing sensitive information when using them, as hackers can easily intercept your data.

Moreover, malware can spread through compromised websites.

When you visit a site that has been infected, it may automatically download malicious software onto your device without your knowledge.

This is often referred to as a 'drive-by download'.

To mitigate this risk, ensure that your web browser and its plugins are updated regularly, as these updates often include security patches that protect against known vulnerabilities.

Another common method of malware distribution is through removable media, such as USB drives.

If you plug in a USB stick that has been infected, it can quickly transfer malware to your computer.

This method is particularly concerning in environments where devices are shared, such as offices or schools.

To safeguard against this, always scan removable media with up-to-date antivirus software before accessing any files.

Additionally, consider disabling the autorun feature on your operating system to prevent automatic execution of potentially harmful files.

‍

Effective Strategies for Defending Against Malware

To defend against malware effectively, it’s important to focus on strategies that help identify, protect, detect, respond, and recover.

Below, are key strategies I use to defend against malware.

‍

Identify: Know Your Environment

Identifying potential risks is the first step in defending against malware.

Understand your environment, including all assets, vulnerabilities, and user behaviour.

By knowing what is at risk, you can prioritize security efforts and minimize exposure.

• Asset Inventory: Keep a detailed inventory of all devices, software, and network components in your environment. This helps you understand what’s at risk.
• Vulnerability Assessment: Regularly assess systems for vulnerabilities. Identify outdated software, unpatched systems, and any weak points.
• User Awareness: Educate users about common threats, like phishing and social engineering. Recognize the signs of an attack.
• Risk Analysis: Understand potential threats and the impact they could have on your operations. This allows for prioritizing security measures.

‍

Protect: Prevent Malware Attacks

Protection involves implementing strong defences to prevent malware from entering your systems.

Keep software updated, use antivirus tools, and limit access to sensitive information.

Taking these precautions can reduce the risk of a successful attack.

• Patch Management: Keep all software up to date. Apply patches regularly to close vulnerabilities before attackers can exploit them.
• Endpoint Security: Use reputable antivirus and anti-malware software on all devices. Enable automatic updates for continuous protection.
• Network Segmentation: Limit the movement of malware by segmenting your network. Keep sensitive data separate and limit access.
• Strong Authentication: Implement multi-factor authentication (MFA) to protect user accounts from unauthorized access.
• Access Control: Limit user privileges to what is necessary for their role. The fewer people who have access to sensitive systems, the lower the risk.

‍

Detect: Identify Threats Early

Early detection is crucial for minimizing malware damage.

Use monitoring tools, analyse logs, and stay informed about emerging threats.

Detecting malware as soon as it appears allows for faster response and less impact.

• Monitoring Tools: Use intrusion detection systems (IDS) and intrusion prevention systems (IPS) to monitor network activity and detect unusual behaviour.
• Log Analysis: Regularly analyse system and network logs for unusual patterns that might indicate an attack.
• Threat Intelligence: Stay informed of emerging threats and indicators of compromise (IOCs). This helps in recognizing attacks before they spread.
• Endpoint Detection and Response (EDR): Deploy EDR tools to identify malicious behaviour on endpoints and respond in real time.

‍

Respond: Take Action Against Incidents

Responding effectively involves having a clear plan in place.

Quickly isolate infected systems, communicate with stakeholders, and analyse the attack to prevent it from happening again.

A strong response limits the impact of malware incidents.

• Incident Response Plan: Develop and maintain a clear incident response plan. Make sure everyone knows their role during an attack.
• Quarantine Infected Systems: Quickly isolate infected devices to prevent malware from spreading further.
• Communication: Notify all relevant stakeholders, including IT teams and possibly affected users, so they can take precautions.
• Root Cause Analysis: Investigate the attack to understand how it happened, and take steps to prevent similar incidents in the future.

‍

Recover: Restore and Learn

Recovery is about restoring systems and learning from the incident.

Use backups to restore data, patch vulnerabilities, and improve your defences based on what happened.

Effective recovery helps you bounce back and strengthen future resilience.

• Data Backups: Regularly back up data and verify that backups are working. Store them offline or in a secure location to protect them from malware.
• System Restoration: Reinstall affected systems from clean backups to ensure all traces of malware are removed.
• Patch and Update: After an incident, make sure that all vulnerabilities are patched to prevent a repeat attack.
• Review and Improve: Learn from the incident. Update your response plans, improve defences, and educate users based on the lessons learned.

Defending against malware requires a proactive approach across all these areas.

By identifying risks, protecting your systems, detecting threats early, responding effectively, and recovering quickly, you can minimize the damage and keep your data safe.

‍

Conclusion

Malware is a real threat.

Understanding the different types helps you guard yourself against potential attacks.

Stay informed and vigilant to keep your digital life secure.

Remember - the ultimate defence against malware is about protection, detection, response and recovery.

Stay safe out there!

‍