What is spyware? Types, examples, and how to prevent it

Think your device is secure? It might not be as safe as you think. Spyware can quietly install itself on your system and start watching everything you do, tracking your activity, logging your passwords, and even accessing sensitive data like your banking details.

That’s why we created this guide: to explain what spyware is, how it works, and what you can do to protect yourself. Because no one should be tracked or monitored without their consent, especially in their own digital space.

Note: Installing spyware or monitoring software on someone else’s device without their explicit consent is illegal in most jurisdictions and often linked to domestic abuse or stalking. This article is provided for educational and defensive purposes only.

What is spyware?

Spyware is a type of malicious software that secretly monitors and collects information from your device without your permission. It can hide in apps, browsers, malicious email attachments, or even deep within your operating system, quietly gathering data like your keystrokes, location, call logs, and login credentials.

Unlike some traditional malware that causes obvious damage, spyware runs silently in the background. It’s designed for unauthorized access, constantly collecting your private information and sending it to a third party without alerting you.

What is spyware on a phone?

On mobile devices, spyware can give attackers full access to your phone, from your texts and call history to your camera, microphone, and GPS location. It often sneaks in through fake apps or phishing links. Once it’s installed, it starts secretly sending your personal data to a third party.

How does spyware work

Spyware embeds itself deep into your device, silently collecting information in the background. It can:

• Log everything you type
• Capture screenshots
• Access your camera or microphone
• Track your physical location

Spyware typically takes advantage of security weaknesses or deceptive tactics to embed itself within your device. Once active, it quietly collects and transmits your information to an external source, often in ways that make it difficult for the average user to detect.

Spyware is more than just a personal privacy issue. If it makes its way into a company’s systems, it can steal sensitive data, expose customer information, or help attackers launch ransomware attacks. It can even be used to steal intellectual property or spy on business operations.

How spyware infects devices

Spyware can infect your device in several ways. Knowing the most common attack vectors is the best way to protect yourself.

Bundled software and freeware

Spyware is often hidden in free downloads, software bundles, or pirated apps. These installers may include “optional” tools that secretly track your activity or inject malicious ads. Always read installation prompts carefully.

Malicious attachments and downloads

Fake documents, PDFs, and software installers are common vehicles for spyware. These files may appear to be invoices, contracts, or updates. Opening them with outdated or misconfigured software can sometimes allow spyware to install silently, though such attacks are uncommon and typically rely on specific vulnerabilities.

Phishing emails

These emails use social engineering to trick you into trusting the sender. Attackers often pose as banks, coworkers, or customer service reps to make their message seem trustworthy. Clicking their links can trigger a spyware infection without you realizing it. Be cautious and follow healthy browsing habits to avoid phishing attacks.

Drive-by downloads

Just visiting a compromised or malicious site can theoretically be enough to install spyware, but this typically requires exploiting rare, high-value browser or plugin vulnerabilities. These so-called “drive-by downloads” don’t require you to click or download anything, but such attacks are extremely uncommon.

Malicious mobile apps

Some mobile spyware hides in shady apps or third-party app stores. These apps often request excessive permissions, then harvest your data, track your location, or even record audio.

Unpatched software vulnerabilities

Outdated apps and systems are easy targets. Attackers take advantage of security flaws in operating systems, browsers, or plugins to install spyware without your knowledge. For example, if you haven’t updated a social media app in a while, they could use an old, already-fixed exploit to infect your phone.

Zero-click exploits

Some high-end spyware goes far beyond typical malware. It can break into your phone without you doing anything at all. These attacks don’t rely on you clicking links or downloading files. Instead, they exploit hidden, often unknown flaws (called zero-day vulnerabilities) in apps like WhatsApp or iMessage. However, such exploits are extremely rare.

Types of spyware

Spyware often leads to data theft, digital surveillance, identity fraud, or other online privacy risks. Here are the most common types you might encounter:

• Keyloggers: Record everything you type, including passwords, messages, and credit card numbers.
• Trojans: Disguised as legitimate apps, they secretly open a backdoor for attackers to spy on you or install more malware.
• System monitors: Track your activity across apps, websites, and files. They can even take screenshots, all without alerting you. Some employer surveillance tools operate in a similar way, recording behavior in the background. When used without clear consent, they can raise serious privacy concerns and blur the line between monitoring and spyware.
• Rootkits: Bury themselves deep in the system (often in the OS kernel) to hide spyware and make it nearly impossible to detect.
• Mobile spyware: Gives attackers access to your GPS, texts, call logs, camera, and microphone, turning your phone into a surveillance tool.
• Password stealers: Target saved or entered login credentials from browsers, password managers, or system memory.
• Adware: Displays unwanted ads and may track your browsing without permission. It often comes packaged with free apps, bundled installers, or is downloaded through shady websites. While not always malicious, adware crosses into spyware territory when it collects personal data to serve targeted ads, slowing down your device and compromising your privacy.

What is an example of spyware?

In recent years, cybersecurity researchers and media reports have uncovered multiple spyware incidents affecting individuals, journalists, and organizations worldwide. These cases often involved:

• Messaging-app lures: Attackers have distributed malicious files disguised as event invitations or other personal messages, tricking users into installing spyware that steals data or banking credentials.
• Zero-day exploits on mobile devices: Some advanced spyware campaigns have leveraged previously unknown vulnerabilities to silently compromise devices and exfiltrate sensitive data over long periods.
• Surveillance of civil society: Reports have described governments or private actors using commercial spyware to monitor journalists, activists, and political opponents, sometimes by remotely activating device microphones or cameras.

How do I know if I have spyware?

Detecting spyware often requires the help of dedicated security tools. However, you don’t need to be a cybersecurity expert to spot the signs yourself.Here are the key warning signs and symptoms that could mean your device is infected with spyware:

• Unusual device behavior: If your phone or computer slows down, crashes, or freezes without reason, spyware could be running in the background.
• Random pop-ups and redirects: Unexpected ads or constant redirects while browsing can signal spyware infection, especially if they happen outside of shady websites. If it feels like you’re being barraged by pop-ups, there’s a good chance you have spyware.
• Unexplained battery drain: Spyware silently operating in the background often drains your battery faster than usual.
• Overheating or high resource use: Spyware eats up CPU and RAM, even when idle.
• New icons or toolbars: If you notice unfamiliar apps, browser toolbars, or shortcuts, they may have been installed as part of a spyware payload.
• Data overages or traffic spikes: Spyware often sends data back to its source, which can show up as unusual spikes in your internet usage.
• Microphone or camera access: If your webcam light turns on randomly, or you notice strange microphone behavior, spyware could be spying on you.
• Disabled security tools: Some spyware turns off your antivirus or firewall to avoid detection.

If you're not sure whether you're dealing with spyware, a virus, or another type of malware, check out these helpful guides:

• How to check if your computer has a virus
• 11 signs your device has malware

How to remove spyware

You have two main options: use dedicated antispyware software or remove it manually (not recommended unless you’re an expert).

1. Use antispyware tools

Most users should rely on antispyware, antivirus software, or dedicated malware scanners to detect and safely remove threats. These tools scan your system for known spyware signatures and behaviors, then quarantine or delete them.

To use these tools:

• Open your security software.
• Run a full system scan (not just a quick scan).
• Let the scan complete before using your device.
• Follow the removal instructions if threats are detected.

Find out more details about removing spyware on Android devices.

2. Manual removal

Manual removal is risky and not recommended for most people, as deleting or modifying system files can damage your device. Unless you’re an experienced IT professional, it’s best to let reputable security software handle detection and cleanup.

How to prevent spyware

Preventing spyware requires a layered approach: good habits, secure settings, and the right tools.

Best practices for any device

Preventing spyware starts with healthy browsing habits and a secure environment. Following these spyware protection tips can significantly reduce your risk and strengthen your overall information security:

• Keep your software updated: New patches fix known vulnerabilities that spyware exploits.
• Disable document macros and scripting: Macros and scripts are small bits of code that can run automatically when you open a file or visit a website. They’re often used in phishing attacks to install spyware without your knowledge. Disabling them, especially in documents and emails, reduces your risk of infection.
• Avoid suspicious links and attachments: Carefully review links before you open them and strictly avoid opening anything suspicious.
• Uninstall unused extensions and apps: Spyware can linger in your browser extensions or in background apps, so uninstall apps that aren’t in use.
• Enable multi-factor authentication: MFA blocks account access even if spyware steals your password.
• Restrict admin rights: Fewer permissions mean less potential damage if spyware does get in.
• Avoid public Wi-Fi without a VPN: Public networks are a hotbed for spyware and other threats. Using a VPN encrypts your traffic, making it harder for attackers to intercept your data.
• Stay informed: Knowing current threats makes you harder to trick. Follow trusted sources like Krebs on Security or CISA for regular updates on new spyware tactics and cyber threats.

Security tips for mobile devices

If you want to protect your mobile device, there are a few more steps to consider:

• Revoke unnecessary permissions: Don’t give apps access to your contacts, camera, location, or microphone unless it’s absolutely necessary. Check your settings and revoke permissions from apps you don’t use or don’t trust.
• Use biometrics: Features like fingerprint scanners or Face ID make it harder for unauthorized users to access your phone. While not foolproof (biometrics can be spoofed), they do add an extra layer of protection.
• Avoid jailbreaking or rooting your device: Disabling your phone’s security restrictions might give you more control, but it also makes it more vulnerable to spyware and other threats.

Recommended security software

Good habits are essential, but they’re only part of the equation. In addition to the anti-spyware tools already mentioned in this guide, there are other essential security software you should consider. While no single product can offer total protection, combining multiple layers of defense dramatically reduces your risk of spyware infections.

Here are the key tools to include in your setup:

• Antivirus: This software scans your system for malware, including some forms of spyware, by detecting known malicious files and suspicious behavior. While many devices come with built-in antivirus, third-party solutions often offer more advanced detection and faster updates.
• Smart firewalls: Unlike basic built-in firewalls (like Windows Defender Firewall), which mostly block incoming threats, smart firewalls also monitor outgoing traffic, a critical feature for spotting spyware trying to send your data elsewhere. They use advanced behavior analysis and rule sets to flag suspicious activity in real time.
• VPNs: As already mentioned, this tool encrypts your internet traffic, helping protect your data from interception by hackers or advertisers. While a VPN can prevent some types of data snooping, it doesn’t detect or remove spyware already on your device.
• Browser security extensions: These extensions monitor websites and links in real time, alerting you to potential threats like malicious downloads or phishing pages, which are common spyware delivery methods.
• Endpoint detection and response (EDR): These enterprise-grade tools monitor company-managed devices for suspicious activity and alert IT teams to potential threats.
• Mobile device management: MDM serves as an enforcement tool that can take action against rogue apps once identified by other security tools, deploy policies to prevent rogue app installations, and remove or quarantine rogue apps based on external threat intelligence. These solutions are typically used by IT teams to manage company devices, not personal ones.

Emerging spyware threats

Spyware is evolving fast, and it’s becoming one of the most dangerous cyber threats today. Modern attackers now have access to advanced tools that make spyware harder to detect, easier to use, and much more dangerous. From AI-powered surveillance to full-blown spyware subscription services, here are some of the biggest trends to watch out for.

AI-powered spyware

AI isn’t changing how spyware collects data; spyware already logs everything it can. But what AI does change is how that data is analyzed. With AI, malicious actors can sift through massive amounts of stolen information more efficiently, making it easier to extract valuable insights, identify patterns, and target victims more effectively.

And it’s not just cybercriminals using it. Even government agencies have started experimenting with it. For example, U.S. forces used AI tools during a military training exercise not only to simulate large-scale data collection but also to interpret and analyze the information, demonstrating how generative AI could support surveillance and intelligence operations.

Spyware-as-a-service

Spyware has become a commercial product. Similar to software-as-a-service (SaaS) models, spyware-as-a-service platforms allow clients to subscribe to powerful surveillance tools with access to technical support, regular updates, and advanced features.

A 2023 report by Google’s Threat Analysis Group and Mandiant found that commercial surveillance vendors (CSVs) were responsible for 64% of all exploited vulnerabilities targeting mobile devices and browsers, highlighting just how widespread these services have become.

While this model lowers the barrier to entry, it also increases the risk of abuse by less experienced or malicious users. Legal and ethical concerns continue to grow, but the popularity of this business model shows no signs of slowing down.

Stealth and zero-day variants

Many modern spyware tools rely on zero-day exploits (previously unknown security vulnerabilities) to gain access to systems before patches are available. These flaws can remain unnoticed for weeks or even months, allowing spyware to operate without detection.

This type of spyware often uses advanced evasion methods to stay hidden from detection tools, like hiding its activity within legitimate system processes or temporarily disabling protective measures. These techniques make modern spyware far more difficult to detect and remove, often requiring specialized tools or expert intervention.