What Is Spyware? How To Avoid This Malicious Software

Learn the risks and warning signs of this dangerous type of malware, as well as how to prevent or remove it.
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Spyware is one of the most sinister cyber threats designed to secretly spy on you. If left unchecked, spyware infections can result in financial loss, blackmail, and even identity theft. In the business world, this malware is often used for corporate espionage. The worst thing? It can be extremely challenging to detect and remove without an advanced antivirus program.

Keep reading to learn what spyware is, how to prevent infections, and what to do if it's already in your system.

In this article
What is spyware?
How can spyware infect your system?
How to recognize a spyware infection
How to protect your system against spyware
What is spyware FAQs
Bottom line

What is spyware?

Spyware is malicious software (malware) designed to operate covertly and perform various invasive actions. It can record your keystrokes, log data, intercept communications, redirect your web traffic, and more.

Spyware attacks have one main goal: to steal your sensitive data. The usual targets include your personally identifiable information (PII), login credentials, financial info, browsing history, location data, computer activity, etc. Hackers can employ different methods and tactics, but they're all after the same thing.

One feature that differentiates spyware from other malware is its customizability. Cybercriminals can tailor it to meet their needs, from highly sophisticated single-target strikes to mass-targeted campaigns.

Different types of spyware explained

As mentioned, malicious spyware can take various forms, from a simple keylogger to massive system monitors. It can infect your computer or mobile device, and you'll need top-level anti-spyware software to remove it.

Some of the most common types of spyware include:

  • Infostealers simply collect your information and send it to an unauthorized third party. They can cast a wide net for anything of value or search for specific data. These system monitors can scan your messages, files, and browsing history and send data and screen captures to their owners.
  • Keyloggers can record and transmit keystrokes from your keyboard (they can cover both physical and software keyboards). A keylogger is a relatively simple spyware program that can cause a lot of damage, especially if it captures your login credentials or financial info.
  • Adware is a particularly annoying spyware that serves pop-up ads in search engines and apps that support them. Some adware variations can also monitor your browsing history to personalize your ads.
  • Trojans, named after the Trojan horse, are disguised as harmless software until you execute them on your system. If you do, they can perform any number of malicious actions. Removing a Trojan before you execute it is essential for your protection.

How can spyware infect your system?

Spyware can infect your system in a number of ways. A successful installation usually relies on your help or exploits a software vulnerability. We outline some of the most common infection vectors below.


Phishing attacks will try to trick you into installing spyware by having you click a malicious link or visit a fake website. Phishers often impersonate well-known companies to build trust with their victims. Learning to recognize phishing messages will help you block these scams.

Software security vulnerabilities

Spyware can exploit outdated software and infect your system without your direct action. You can easily prevent these attacks by keeping your system, programs, and apps up to date.

Unsecured Wi-Fi networks

Criminals can intercept your traffic on unsecured networks and launch anything from Man-in-the-Middle to Evil Twin attacks. Spyware is only one of the nasty surprises they can throw at you in these situations.

Rooting or jailbreaking phones

Rooting (for Android) and jailbreaking (for iOS) allow you to bypass the manufacturer's restrictions and gain full access to your mobile operating system (OS). They're also ideal for infecting your device with mobile spyware.

"Unlocking" your mobile device allows you to install unvetted third-party apps. Many of those will come with malware that activates upon installation. We don't recommend rooting or jailbreaking anything since it makes it much easier for criminals to hack your iPhone or Android devices.

How to recognize a spyware infection

Spyware typically works quietly in the background, making it difficult to spot. That said, we recommend watching out for these red flags:

  • Strange pop-ups: If you see pop-up ads while not browsing the web, your system is likely infected with adware.
  • Redirects in your browser: A web browser that ignores your input and takes you to suspicious websites is a huge red flag.
  • Poor device performance: Overheating, sluggish performance, crashes, and quick battery drainage are potential signs of malware infection. However, they could also be signs of expected wear and tear in older devices.
  • Sudden data usage spikes: Spyware also needs bandwidth to transmit the data it collects. If you see unexpected spikes in data usage, we recommend running a malware scan.
  • Unusual activity: Spyware can launch web searches, start apps and programs, or open files on its own. Whatever happens without your input should be considered a red flag.
  • Browser hijacking: Spyware can modify your browser. Some examples include adding extensions and toolbars, changing your settings, setting a new homepage, and redirecting your searches.
  • Security software disabled: Spyware can protect itself against your security programs; it can turn off your antivirus tools and prevent you from turning them back on. It can also block updates.
  • Strange messages: If your contacts start getting strange messages you didn't send, spyware is likely trying to propagate to other devices.

How to protect your system against spyware

As mentioned, spyware can be difficult to detect and remove. Therefore, it’s always best to focus on proactive protection rather than dealing with the fallout. Here's what you can do:

  1. Update your software regularly. This is one of the simplest and most effective tips we can give. Software updates often include security patches and other fixes.
  2. Check your downloads. Make sure your downloads come from trusted sources. This especially goes if you're downloading third-party apps onto your rooted or jailbroken phone.
  3. Don’t click suspicious links. Most web browsers let you hover over a link to see where it leads. Always check the web address before clicking. Don't click if you can’t verify the link or if the source seems suspicious.
  4. Enable your firewall. A firewall is an essential security tool that monitors your network and blocks unauthorized traffic.
  5. Use a strong antivirus program. Solid anti-malware software can block spyware attacks and remove the existing infection.

The best antivirus programs for blocking and removing spyware

A good antivirus program is one of the few ways to remove existing spyware infections. It also allows you to block most hack attacks and keep your desktop and mobile devices as safe as possible. Here are some of our top antivirus picks for flagging and removing spyware:

  • TotalAV is our pick for the best antivirus tool of 2024. It offers comprehensive malware protection and can even flag phishing messages. Every TotalAV package has an ad blocker that can remove annoying pop-ups and other malicious ads.

    Get TotalAV | Read TotalAV Review
  • AVG allows you to bundle Internet Security, VPN, and TuneUp tools into one convenient package. One AVG subscription can protect you against most malware, phishing, hack attacks, and online privacy risks while optimizing your device's performance.

    Get AVG | Read AVG Review
  • Avast offers solid protection against malware, scams, and fake malicious websites. It can also block hackers from accessing your files remotely. In addition, it allows you to open suspicious files in a safe environment, which keeps your device protected.

    Get Avast | Read Avast Review

All our picks also include limited free versions, which could cover some of your cybersecurity needs on a budget.

What is spyware FAQs


What is spyware, and why is it a problem?

Spyware is a type of malware designed to spy on you and steal your sensitive data. An infection can result in identity theft, data leaks (including private documents, photos, and videos), financial loss, blackmail, and much more.


Can spyware be installed without you knowing?

Yes, criminals can infect your desktop or mobile device with spyware without your knowledge. In fact, that's the whole point of this malware — to steal your data without causing visible symptoms on your device. For example, a keylogger secretly installs on your device and then operates silently, recording everything typed on your device. Spyware is often only detected when users run a malware scan with antivirus software.


Is spyware a virus?

No, spyware is not a virus. Spyware is a type of malware. A computer virus is also malware, but its purpose and function are different. Spyware is designed to sit on a device quietly and steal information while evading detection. Conversely, a virus is designed to replicate itself and spread throughout the network, much like a real-life virus.


What private data can spyware collect?

Spyware can collect any data on your device, including messages, documents, photos, and videos. Depending on the type of spyware, it can also log any input on your device, including what you type on your keyboard. Common data targets include usernames, passwords, credit card numbers, and bank account information.


How do I know if my device has spyware?

Spyware can be tricky to detect. Some red flags include frequent pop-ups, overheating or poor performance without an obvious cause, sudden changes to your web browser, and new apps you didn’t install. Antivirus programs like TotalAV or Avast can also help detect malware on your computer.


Can I remove spyware from my device?

Yes, spyware can be removed. It’s not easy, though — you’ll almost always need antivirus software capable of detecting and removing malware from your computer. (We recommend TotalAV.) Your best bet is to avoid spyware by following online safety best practices, such as downloading software from trusted sources and keeping your devices updated with the latest software.

Bottom line

Spyware is malware designed to secretly log your activities and data. As such, we consider it a serious privacy and security risk. Left unchecked, a spyware infection can lead to financial losses, identity theft, blackmail, data leaks, and more.

Spyware can be incredibly hard to detect once it’s on your device. For that reason, your best defense is to prevent infections altogether. It’s important to have good cybersecurity habits, like avoiding suspicious links, to block attacks.

Spyware can be challenging to remove completely. We recommend installing an advanced antivirus program that can deal with top-tier threats. These tools can also help you block known spyware disseminators (like phishing emails) and flag malware-carrying files and programs.

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Author Details
Dave Schafer is a professional writer with a decade of experience specializing in cybersecurity. His expertise spans gadgets, technology, and the internet, with a focus on topics such as routers, hardware, and VPN product comparisons.