What is Spyware? How Do You Protect Your Devices?

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A Quick Guide: What is Spyware? How Can You Protect Yourself?

As its name suggests, spyware is a type of malware that can spy on you. This could be through keyloggers that record your keystrokes to obtain passwords, logins, emails, and other sensitive data. Spyware can also highjack your browser to get a hold of browsing history or take control of your camera to take photos and video. Spyware is often used to commit identity theft, empty bank accounts, or collect and sell your private information to third parties.

To detect and remove spyware, we recommend using a strong antivirus program that can root out the malware. A premium program like Bitdefender will keep you and your devices safe.

Protect Yourself from Spyware with Bitdefender

Want to learn more about the different types of spyware hiding online? Need some tips on how to prevent attacks? Make sure to read our full guide below.

Spyware is one of the oldest types of malware and continues to be one of the most threatening. As its name implies, spyware is a certain type of software that spies on you when you’re using your computer or mobile device. It’s important to be aware of the possible signs of spyware so you can recognize when you’ve been infected and take action to remove it.

But what is spyware, exactly? How can you detect it and protect your devices from it? Read on to find out more about this cyberthreat.

What is Spyware?

Spyware is a type of malicious software that infects your computer and mobile devices. It tracks your online activity and collects your personal information without your knowledge or consent. It gathers this personal data by capturing keystrokes, email addresses, web form data, tracking cookies, and credit card numbers.

There are different types of spyware. Each gathers different kinds of information and will be discussed in more detail down below.

Infographic showing different types of spyware

Password stealers

This type of spyware gathers passwords from infected devices. These include passwords stored on web browsers and login information for your PC.

Banking Trojan malware

Banking Trojans are a type of spyware that records credentials from banks and other financial institutions like brokerages or digital wallets. Trojans locate security vulnerabilities in browsers and tamper with web pages and transactions without the user or institution knowing about it.


This kind of spyware scans infected devices for information such as usernames, passwords, browser history, log files, documents, and media files. The software then transmits the information to another server or stores it on your PC, where hackers can access it.


Sometimes called system monitors, this type of spyware records your computer activity. It can track your keystrokes, the websites you visit, search history, and email correspondence. It often takes screenshots of your activity as well. Some kinds of keyloggers can also collect information from other connected devices, such as printers.

Browser highjackers

Browser highjackers quite literally highjack your browser: they allow hackers to change your browser settings and visit (fraudulent) websites you didn’t ask it to visit. Though this type of malware usually falls under adware, it can also carry spyware components. Adware is an annoyance and is more or less harmless to your device, but if browser highjackers carry spyware, they might collect your data and sell it to third parties. Malicious actors might even use it for their own gain. If you suspect you’ve been infected with adware, it’s better to play it safe and remove it at once.

How Do You Know if Your Device is Infected With Spyware?

There are a few common signs that might hint at a malicious spyware infection. Though these can be issues that signal any malware infection, they can also be attributed to spyware specifically. You might worry if someone is spying on your smartphone, or find that your computer is acting up in an odd way. Could this be spyware?

If you’ve noticed your devices exhibiting any of the symptoms mentioned below, take notice and take action.

Infographic showing how do you know if your device is infected with spyware

Poor operating system performance

When a device is loaded with spyware, it can drag down the performance of your operating system. This is because it’s constantly running in the background, taking up processor power and disk space. You might notice lots of lagging, or applications and files taking an unusually long time to open. While this could be down to you using an older computer or device, sluggish performance is also a big red flag for malicious spyware infections.

Freezing and crashing

Having a document or spreadsheet freeze or having your entire system crash while you’re watching a video online can be frustrating. While this does happen to everyone’s device from time to time, you need to start worrying if it becomes a regular thing. In that case, it could be caused by spyware.

Pop-up ads

Pop-up ads are a dead giveaway for malware infection, especially when you’re not using the internet. You might even see your own name in the ads. Though adware and other viruses could be responsible for invasive ads, it’s also a common sign that spyware has made its way to your device.

Mysterious new files or deletion of your old files

If you notice that new files have mysteriously appeared on your device, that could be a sign of spyware. You may also notice that your own files have been deleted or moved to strange folders or places on your device. Shortcuts on your desktop or toolbar might also be missing, or not actually take you to your intended destination. All of these signs point to a spyware infection.

Browser issues

There are all sorts of browser issues that can occur when you’ve got spyware on your computer. You might see an insecure browser pop up to complete searches for you. You might be rerouted to a strange homepage when you click your regular browser. You might even automatically be directed from secure HTTPS sites to insecure HTTP sites. If your browser or browser security settings are acting up, it could be because of a spyware infection.

What are the Risks?

There are two major risks associated with spyware:

  • Spyware steals personal information and can put you at risk for identity theft. It can access your browsing history, email accounts, and logins for online banking and shopping accounts, as well as social media accounts. This is more than enough information to steal your identity. If the spyware gets your banking or credit card information, hackers can even use that information to make purchases in your name or sell your data to other parties.
  • Spyware can cause significant damage to your computer and other devices. It can drain your computer’s memory and cause it to run slowly, freeze, crash, or overheat. Spyware can also alter search engine results, change your homepage and settings, or deliver malicious websites to your browser.

How Does Spyware Infect Your Computer?

There are many different ways that spyware can infect your device. Here are some of the most common ways it gets delivered:

Infographic showing how does spyware infect your computer

Drive-by downloads

In a drive-by download, a website or pop-up window automatically downloads spyware onto your device. You might get a warning giving you the name of the software and requesting permission to install it, but in many cases, there is no warning at all.

Software downloads

Some internet software downloads, particularly file-sharing applications, can also install spyware on your devices. This is most common with free versions of software you normally have to buy. Malware-infected games, for instance, contain all kinds of harmful elements, including keyloggers and even computer viruses.

Fake anti-spyware programs

In some cases, spyware is disguised as an anti-spyware program. These programs convince you that they will detect and remove spyware from your machine. After you run them, you’ll get a message that your computer is clean when in fact they have installed spyware on it. Even if you remove the fake program, the spyware will remain on your computer. You’ll need a strong antivirus program to detect and delete it.

Spyware, like most other kinds of malware, can be sent in a link or an email attachment. Never click on an unfamiliar link or attachment and don’t open emails from an unknown sender. Doing so could result in spyware being downloaded and installed on your computer. Clicking on malicious links can also infect your device with a worm. These worms are used to spread malicious software using the network your device is attached to.

Mobile device spyware

Some types of spyware target mobile devices. This type of spyware infects iPhone and Android devices when you install an app that has malicious code. Some of these apps are legitimate, but have been altered to contain malcode, others are malicious, and some have fake download links.

What Can I Do If I Detect Spyware On My Device?

Spyware can be extremely difficult to detect. But remember that warning signs include:

  • An excessive number of pop-ups
  • Strange notifications
  • Your browser spontaneously redirecting you
  • Your browser’s home page changing
  • Your computer being extremely slow to boot up, open programs, or save files
  • Your mobile device being slow when opening apps

If you suspect that there is spyware on your device, you need to remove it immediately. We don’t recommend trying to remove it manually, as you may not be able to get all of the malicious components out on your own.

You’ll need to purchase a powerful anti-spyware scanner that has advanced spyware removal capabilities. This type of program removes spyware from your device and repairs any altered files or settings.

The Three Best Anti-Spyware Programs

There are plenty of good spyware removal tools available to consumers online. Here are our top three recommendations to combat and block spyware infection. If you suspect that you already have spyware on your device, these top scanners should be able to find it.

1. Bitdefender: Strong deep scans of your entire system

Screenshot of Bitdefender antivirus website homepage with logo in the corner

Bitdefender has become one of the biggest names in antivirus software, and for good reason. It provides real-time protection against most malware that can steal personal information. It’s also got anti-phishing and anti-fraud systems, and a strong deep scan that can root out even the most covert malware and spyware threats. Take a look at our deep dive into Bitdefender antivirus here.

Remove Spyware with Bitdefender

2. Avast Antivirus: Real-time protection and webcam safety

Another antivirus program we recommend to combat spyware is Avast. Avast Free Antivirus has a strong malware scanner and real-time protection against malware. When you upgrade, you’ll get real-time protection against suspicious sites, attachments, and phishing attempts that might carry spyware. Since spyware can also hijack your camera, Avast also provides webcam protection. Check out our full review of Avast Antivirus here.

Remove Spyware with Avast

3. AVG Antivirus: Premium anti-spyware features

AVG’s free antivirus has real-time protection, a strong firewall and a great antivirus scanner that will help detect and remove spyware from your device. When you upgrade to a premium plan, you get a more advanced firewall and anti-spyware features like encryption of folders to protect against snooping malware. If you navigate to a malicious website, it will also block any unsafe links. Check out our full review of AVG here.

Remove Spyware with AVG Antivirus

How Can I Prevent Spyware?

If you have a device that connects to the internet, there is always the risk of spyware and other kinds of malware getting on your device. However, there are a number of steps you can take to decrease the risk of spyware infection. Here are some ways you can help protect your devices from spyware:

Infographic showing how can you prevent spyware

Adjust your browser security

Many browsers allow you to adjust your security options on a scale ranging from low to high. Find out what the options are for your particular browser, be it Chrome, Mozilla, or Microsoft Edge. Some browsers can even act as a firewall against cookie installation and unwanted operations.

Don’t trust pop-ups

Oftentimes, ads and offers that appear in pop-up windows may contain viruses or spyware. Some of these pop-ups claim that your computer has a virus, or thaty they’re an extension to improve your online experience. Don’t click “Agree” or “OK” to close the pop-up. Always click on the red “X” instead.

Practice internet safety

As with other kinds of malware, spyware is often delivered in a link or attachment. Be wary of emails from unknown senders, and never click on links or attachments if you don’t know what they are. For more information on warning signs in emails from strangers, have a look at our article on phishing.

Use antivirus or anti-spyware programs

We hope that you’ve already got a premium antivirus program on the device you’re using to read this. Sometimes spyware is disguised as anti-spyware tools, so it’s important to use a reliable provider. If you couldn’t choose between one of the suggestions we mentioned earlier, take a look at our top 5 antivirus recommendations, all of which can protect you against spyware as well. Once you purchase the program, make sure to update it regularly for maximum effectiveness.

How Common is Spyware?

Spyware is a quite common type of cyberattack and can be used for anything from invasive advertising and identity theft to cyberstalking and sextortion. Spyware’s heyday was in the late 90s and the turn of the millennium, with the first anti-spyware program being released in 2000.

A 2004 survey conducted by the National Cyber Security Alliance turned up some shocking results. The survey estimated that 80% of internet users’ devices had been affected by spyware. 89% of those infected had no idea the spyware was on their device.

In recent years, its usage has declined somewhat as ransomware and cryptojacking have become much more widespread among cybercriminals due to their profitability. Even so, spyware remains a constant threat to individuals and businesses alike, as you can see in the examples below.

Recent Examples of Spyware

Though ransomware has stolen the headlines in cybersecurity news as of late, there have also been some high-profile spyware cases in recent years. Here are a few examples:

Pegasus spyware

If you’re reading up on spyware, you may have heard of Pegasus. Though Pegasus Spyware — developed by the Israeli tech firm NSO Group — was built to combat terrorism and other threats, governments and bad actors have misused it to target journalists, activists, and politicians, among others.

It can easily infiltrate iOS and Android devices through software vulnerabilities and retrieve emails, encrypted messages, GPS coordinates, calendar entries and photos or videos. It can do this all through zero-click attacks — which means victims don’t even have to mistakenly download files, attachments, or malicious apps for the spyware to start working. Attackers can even operate the phone remotely, switching on video or taking photos whenever they choose.

Pegasus is particularly difficult to detect and remove, and the NSO Group was sued by Apple for infecting its devices and compromising their users’ privacy in November 2021.


FluBot is a malicious piece of spyware known for hopping between Android devices via fraudulent messages and notifications. Users get a notification stating they have a missed voicemail, SMS message, package delivery, or even a FluBot infection warning. Once clicked, the spyware gets downloaded to the Android mobile device.

Once on mobile devices, the malware makes its way to banking and cryptocurrency apps to begin capturing sensitive data like credit card details, bank account information, browser pages, and other sorts of personal information. It also searches out contact lists and spreads to other devices.


The DarkHotel spyware is a sophisticated cyberattack targeting public hotel Wi-Fi connections. Believed to be linked to the North Korean hacking group of the same name, the attack focuses on higher-level executives staying in premium and luxury hotels — though anyone can fall victim.

When logging into the hotel’s public connection, victims are actually connected to a malicious server that prompts them to download a software update. What appears to be legitimate software is actually spyware that looks to access the victim’s device and log sensitive financial data, insider knowledge or other valuable company data.


CoolWebSearch is a spyware threat that’s been around since 2003, and still manages to infect Windows devices today. Experts have said it’s one of the most aggressive spyware programs to ever be created.

The program hijacks your browser and installs odd-looking browser bookmarks and desktop shortcuts on your device. You’ll also be subjected to pop-ads that take you to pornography and data collecting sites. All information obtained from CoolWebSearch goes back to the site for collection and selling to third parties.

Agent Tesla

Cybersecurity experts have long considered Agent Tesla to be one of the most complex spyware programs that hackers use. It’s also extremely stealthy and difficult to detect. It typically infects devices through phishing emails and malicious attachments that are mistakenly downloaded.

It sneaks onto devices as a Trojan, then is activated as a Remote Access Trojan (RAT), which allows attackers to gain total control of your device. Keylogging spyware components mixed with the remote access control can be devastating. Once passwords and logins have been stolen, the attacker can log in when the owner isn’t using the device and take complete control of accounts.

Want to learn more about malware threats, cybercrime, and how to protect yourself? Make sure to check out our entire sections on malware and cybercrime. Here are a few articles you might find helpful:

Spyware: What is it and How to Protect Yourself - Frequently Asked Questions

Do you have more questions on spyware? Want to learn more about types of spyware and how to protect yourself? Click on any of our FAQs below for an answer.

Spyware is malicious software that logs and records sensitive data like passwords, login info, bank account information, credit card and debit card numbers. There are several types of spyware:

  • Keyloggers
  • Password stealers
  • Banking Trojans
  • Infostealers
  • Browser highjackers.

Read our full article for more information.

The most common types of spyware are browser hijackers. These malicious programs take over browsers, redirect your homepage, and blast you with pop-up ads. While some forms of adware are relatively harmless, others can collect your sensitive data. For more information on spyware, read our full article.

There are a few common signs of a spyware infection:

  • Sluggish, poorly performing operating system
  • Applications or device freezing and crashing
  • Pop-up ads
  • Your browser redirecting you to a strange homepage
  • Files mysteriously appearing or disappearing on your device

You’ll need a premium antivirus program to detect and remove spyware.

Tech journalist
Taylor is a tech writer and online journalist with a special interest in cybersecurity and online privacy. He’s covered everything from sports and crime, to explosive startups, AI, cybercrime, FinTech, and cryptocurrency. For VPNOverview.com he follows news and developments in online privacy, cybersecurity, and internet freedom.
Tech journalist
Tove has been working for VPNoverview since 2017 as a journalist covering cybersecurity and privacy developments. She has broad experience developing rigorous VPN testing procedures and protocols for our VPN review section and has tested dozens of VPNs over the years.