What is Spyware: How It Works and How to Stop It?

Bisma Farrukh

Bisma Farrukh

August 1, 2025
Updated on August 1, 2025
What is Spyware: How It Works and How to Stop It?

That innocent-looking device in your pocket? It’s recording your conversations, tracking your location, and sending your most private moments to complete strangers, all while you sleep peacefully, completely unaware. This is spyware and it’s already inside 1 billion devices worldwide.

Right now, as you read this, advanced spyware is silently stealing data from phones, laptops, and tablets across the globe. Unlike ransomware that screams “YOU’VE BEEN HACKED!” or viruses that crash your computer, spyware is the invisible, patient, and devastatingly effective.

Globally, spyware is increasingly being used not just by cybercriminals, but also in state-sponsored surveillance and corporate espionage. As spyware becomes more advanced and more complex to detect, understanding how it works and how to defend against it has never been more critical.

What Is Spyware?

Spyware is malicious software designed to secretly infiltrate devices, computers, smartphones, and tablets and gather information without the user’s consent. The term merges “spy” and “software”. It broadly includes any code that collects and sends data, such as browsing habits, passwords, keystrokes, screenshots, and location data, back to an attacker or third party, often for profit or surveillance.

While some forms of tracking (e.g., legitimate analytics cookies) are legal and transparent, spyware intentionally hides its presence, operates without notice, and usually violates privacy expectations.

Spyware in cybersecurity is a serious threat due to its stealth, persistence, and ability to harvest sensitive data. It’s considered a form of malware, but its aim is espionage and theft rather than disruption. The growing ubiquity of spyware has made it a key concern:

  • Up to 80% of internet users have likely encountered some form of spyware on their systems, often without realizing it.
  • Many organizations and individuals worldwide suffer from hidden spyware infections that allow attackers to exfiltrate confidential data over time.

Globally, businesses are grappling with mounting spyware detections. In Africa, detections rose 14% year‑on‑year from 2024 to 2025, while password‑stealer detections climbed 26%, highlighting spyware’s rapid growth within enterprise environments.

In 2024 alone, spyware attacks increased by 300%, yet most victims only discover the breach months or years later, if ever.

How Does Spyware Work?

Spyware may operate silently, but its process follows a clear and methodical path. Here’s a breakdown of how it typically works:

1.   Infiltration

The first step is gaining access to your device. Spyware often enters through deceptive methods such as malicious email attachments, infected software downloads, compromised websites, or bundled with legitimate-looking applications. In many cases, users are unaware that spyware is being installed.

2.   Installation and Setup

Once the user interacts with the compromised file or link, the spyware installs itself. It may hide within system files, use names that resemble trusted programs, or modify registry settings to ensure it runs every time the device is turned on.

3.   Surveillance

After installation, the spyware begins its core function—monitoring user activity. Depending on its type, it can log keystrokes, track websites visited, take screenshots, read emails, and in some cases, activate the microphone or camera. This phase is designed to remain hidden from the user..

4.   Data Collection

As the spyware continues to monitor behaviour it compiles the collected information. This could include login credentials, credit card numbers, personal messages, or other sensitive data. Some variants are even capable of intercepting data in real time.

5.   Data Transmission

The final step involves sending the gathered information to an external server controlled by the attacker. From there, it may be sold, used for identity theft, corporate espionage, or other forms of cybercrime.

How to detect Spyware?

Detecting spyware early can prevent serious data breaches. Here are few reasons:

  1. Unusual System Slowdowns
    Spyware may consume system resources in the background if your device becomes sluggish or freezes frequently.
  2. Pop-Ups and Ads
    Even when your browser is closed, frequent pop-ups or ads can indicate an adware or spyware infection.
  3. Unexpected Battery Drain (Mobile Devices)
    Spyware often runs continuously, leading to faster battery drain than usual.
  4. Increased Data Usage
    Spyware might transmit data in the background if your internet or mobile data usage spikes without explanation.
  5. New or Unfamiliar Programs
    Check for software or apps you don’t remember installing; spyware often hides under innocent-sounding names.
  6. Changes in Browser Settings
    Homepage or search engine changes, unknown toolbars, or redirected searches are signs of browser hijackers.
  7. Security Software Warnings
    Your antivirus or anti-malware software may flag or quarantine suspicious files; don’t ignore these alerts.
  8. Camera or Microphone Activates Unexpectedly
    If you notice the webcam light turning on or microphone usage without your action, spyware may be listening or watching.
  9. Overheating
    Devices infected with spyware often overheat due to constant hidden activity.
  10. Check for Suspicious Background Processes
    Use Task Manager (Windows) or Activity Monitor (macOS) to look for unknown or high-resource processes.
How to detect Spyware

Types of Spyware

Spyware encompasses multiple categories, each tailored to specific goals:

1. Adware (Advertising-Supported Spyware)

  • Adware is one of the most common and least sophisticated forms of spyware. While it might seem harmless, it can be incredibly invasive. 
  • Adware tracks your browsing habits, such as websites visited, search queries, and time spent online, and uses that data to serve targeted ads. In many cases, this data is sold to third-party advertisers.
  •  Some adware also comes bundled with freeware or shareware, installing itself without the user’s knowledge. Although not always malicious, adware becomes problematic when it slows down systems, overwhelms users with pop-ups, or collects data without proper consent.

2. Keyloggers (Keystroke Loggers)

  • Keyloggers are spyware programs designed to record every keystroke made on a device, including login credentials, banking information, emails, chat messages, and any other typed content. 
  • The stolen data is usually sent to a remote attacker. Keyloggers are commonly used in both cybercrime and surveillance, and can be installed through phishing attacks, malicious downloads, or as part of a Trojan payload. 
  • Hardware versions of keyloggers also exist, and they are physically attached to a keyboard and a computer. Some advanced keyloggers are even capable of capturing clipboard contents and taking screenshots.

3. Trojans and Trojan-Based Spyware

  • A Trojan is a type of malware that disguises itself as legitimate software. Trojan-based spyware typically provides backdoor access to a system, allowing attackers to monitor activities, steal data, and control the device remotely. 
  • Unlike viruses, trojans don’t replicate themselves; instead, they rely on social engineering to trick users into installing them. 
  • These trojans often come embedded in email attachments, fake software updates, or malicious links.

4. System Monitors

  • System monitoring spyware goes beyond keylogging by capturing a wide range of activities on a device. These tools can record screen activity, clipboard content, email communications, websites visited, and even microphone or webcam input.
  •  System monitors are often used in corporate environments for employee surveillance, though they can be abused for malicious purposes. 
  • Some parents also use them for child monitoring, but system monitors can become powerful surveillance tools in the hands of attackers.

5. Browser Hijackers

  • Browser hijackers modify web browser settings without user permission. They typically change the default search engine and home page or install unwanted toolbars. More dangerously, they can redirect traffic to malicious websites, intercept search queries, and track online behavior. 
  • These programs can also slow down browser performance and open the door to further infections. In many cases, browser hijackers are bundled with helpful free software or browser extensions.

6. Mobile Spyware

  • Mobile spyware targets smartphones and tablets, allowing attackers to monitor calls, messages, GPS location, app usage, and even microphone or camera activity. 
  • Unlike basic PC spyware, mobile variants often require device rooting (Android) or jailbreaking (iOS) to gain full access, though some advanced spyware can bypass these restrictions. 
  • Mobile spyware is often disguised as harmless apps or utilities like battery savers or parental control apps.

7. Infostealers (Information Stealing Spyware)

  • Infostealers are designed to locate and extract specific types of information from a system. This may include saved passwords, browser cookies, cryptocurrency wallets, authentication tokens, and autofill data. 
  • Once collected, the information is transmitted back to a command-and-control server. Infostealers often operate silently, and users may not realize their data has been compromised until unauthorized access or identity theft occurs. 

8. Commercial Spyware and Stalkerware

  • Stalkerware is commercial spyware often marketed as parental control or employee monitoring tools. While legal in some jurisdictions, many stalkerware apps operate without user consent and have been widely abused in domestic abuse and harassment cases. 
  • These tools can track location, access private messages, monitor calls, and view browsing history. Major security vendors like Kaspersky and Norton have added detection signatures to classify and block stalkerware.

Risks of a Spyware Infection

Whether targeting individuals, businesses, or government systems, spyware puts sensitive data, privacy, and system functionality at risk. Below are some of the most common and damaging risks associated with spyware:

1. Loss of Personal and Financial Information

One of the most immediate threats posed by spyware is the theft of personal and financial data. Keyloggers and form-grabbing spyware can capture login credentials for online banking, e-commerce platforms, and digital wallets. Once attackers obtain this information, they can commit identity theft, make unauthorized purchases, or empty bank accounts. 

2. Identity Theft and Fraud

Spyware can collect enough personal data, such as your full name, address, phone number, and government-issued IDs, to allow cybercriminals to impersonate you. This stolen identity may be used to open credit cards, apply for loans, or conduct illegal activities in your name. Victims often face long-term financial damage and emotional stress while trying to recover from identity fraud.

3. Corporate Espionage and Data Breaches

In businesses, spyware poses a major risk to intellectual property, trade secrets, and confidential communications. Cybercriminals use spyware to monitor emails, steal proprietary documents, or gain access to company intranets. 

Competitors, hackers-for-hire, or even nation-state actors may deploy spyware to conduct corporate espionage, leading to multimillion-dollar losses and legal consequences. A 2023 IBM report found that the average cost of a corporate data breach caused by spyware was approximately $4.62 million.

4. Performance Degradation and System Instability

Even if spyware isn’t stealing sensitive data, it can severely affect system performance. Many spyware programs run multiple background processes, consuming RAM and CPU resources. This results in slow boot times, system crashes, and decreased productivity. 

For businesses, widespread infections can lead to downtime and IT support costs, while personal users experience frustrating slowdowns and software glitches.

5. Invasion of Privacy

It can capture everything from browsing habits and private conversations to GPS locations and webcam footage. This constant monitoring can completely compromise personal privacy. 

In some cases, spyware has been used in abusive relationships as stalkerware, tracking victims without their knowledge. The psychological impact of such surveillance can be severe, especially if sensitive photos, messages, or locations are leaked or misused.

Organizations that fail to protect customer or employee data may face lawsuits or regulatory penalties if spyware results in a data breach. For instance, under regulations like GDPR (Europe) or HIPAA (U.S. healthcare), companies can be fined millions for failing to secure private data. Even if unintentional, a spyware infection can put organizations on the wrong side of data protection laws, damaging both finances and reputation.

7. Unauthorized Access and Remote Control

Some spyware variants include backdoor functionality, allowing attackers to control a device remotely. They can install additional malware, enable the webcam or microphone, or manipulate system settings. 

In the wrong hands, this control can be used to stage larger attacks, such as the deployment of ransomware or inclusion in a botnet.

8. Spread to Other Devices and Networks

Spyware often doesn’t stop at a single device. Once it infects a computer or mobile phone, it may spread to other devices on the same network, especially in poorly secured environments. This can compromise entire household networks or corporate infrastructures. Infected machines may unknowingly become vectors, forwarding infected links or files to others.

Measures for Spyware Protection 

The following are the measures for spyware protection:

1. Use Anti-Spyware and Antivirus Software

  • Install reputable anti-spyware software (e.g., Malwarebytes, Spybot Search & Destroy).
  • Use comprehensive antivirus suites that include spyware detection.
  • Keep these tools updated regularly.

2. Keep Systems and Software Updated

  • Install operating system updates (Windows, macOS, Linux).
  • Regularly update browsers, plugins, and commonly used apps (e.g., Adobe Reader, Java).
  • Enable automatic updates if possible.

3. Practice Safe Browsing

  • Avoid downloading files or software from untrusted websites.
  • Do not click on suspicious links in emails or pop-ups.
  • Use browsers with built-in phishing and malware protection (e.g., Chrome, Firefox).

4. Limit Administrative Access

  • Use a standard user account for daily activities.
  • Only use admin rights when necessary (e.g., installing software).
  • Disable autorun for USB devices and CDs.

5. Use Strong Authentication and Access Controls

  • Use strong, unique passwords and change them regularly.
  • Enable two-factor authentication (2FA) where available.
  • Lock your computer when not in use.

6. Secure Mobile Devices

  • Install apps only from official app stores.
  • Review app permissions before installing.
  • Use mobile security apps

7. Avoid P2P and Torrent Downloads

  • Spyware is often bundled with free software and torrents.
  • If you must use them, scan all downloads with antivirus tools before opening.

8. Configure Firewalls and Network Settings

  • Use a hardware firewall (router-based) and a software firewall.
  • Disable unused services and ports.
  • Use a VPN on unsecured networks like AstrillVPN.

9. Educate Yourself and Others

  • Learn how to recognize phishing attacks and suspicious behavior.
  • Teach family or coworkers about safe computing habits.

10. Monitor and Audit Systems

  • Use system monitoring tools to detect unusual activity.
  • Check your browser extensions and installed software regularly.
  • Review system logs for suspicious events.

How to remove Spyware?

The following steps should be taken for spyware removal:

 Step 1: Disconnect from the Internet

  • It prevents spyware from sending out your data or downloading more malicious files.
  • Disconnect Wi-Fi or unplug Ethernet temporarily.

Step 2: Enter Safe Mode

  • Windows: Restart your computer → Press F8 or hold Shift while clicking “Restart” → Choose Safe Mode with Networking.
  • macOS: Restart and hold Shift during boot to enter Safe Mode.

Safe Mode limits the spyware’s ability to run at startup.

Step 3: Use Anti-Spyware Tools

  • Use one or more reputable tools. Use Paid Tools for more advanced removal.
  • Run a full system scan and follow prompts to quarantine or delete detected spyware.

Step 4: Manually Remove Suspicious Programs (Advanced)

  • Go to Control Panel > Programs & Features (Windows) or Applications (macOS).
  • Uninstall unknown or suspicious programs.
  • Check browser extensions and remove any you don’t recognize.

Step 5: Clear Browser Data and Reset Settings

  • Clear cookies, cache, and history.
  • Reset browser to default settings.

Step 6: Check Startup Items and Background Processes

  • Windows: Ctrl + Shift + Esc → Task Manager → Startup tab
  • macOS: System Settings > Users > Login Items
  • Disable any unknown or unwanted entries.

Step 7: Update OS and Software

  • Install the latest security patches.
  • Outdated software can be exploited by spyware.

Real-Time Spyware Examples

Pegasus (NSO Group)

  • Deployed on iOS and Android via zero‑click exploits; reads messages, hijacks microphone, camera, collects passwords, tracks location, supports popular chat apps like WhatsApp, Telegram, Skype, Gmail. Used to spy on journalists, activists, and diplomats worldwide.

Hermit Spyware

  • Used in Kazakhstan and Italy; infects via fake carrier messages, uses Apple Developer Enterprise certificates for iOS installation, and gains root on Android. Capable of call/log tracking, audio recording, photo, and message access.

Daxin

  • Kernel‑level Windows backdoor has been suspected of espionage across Asia and Africa for over a decade. Blends in with legitimate TCP traffic to evade detection.

Operation Triangulation / TriangleDB

  • Complex iOS targeted attack chain using four zero‑day vulnerabilities; infects thousands of Russian diplomats and officials via invisible iMessage attachments, loads memory‑resident implant capturing credentials, chats, geolocation, voice recordings.

Commercial Surveillance Tools and Smaller Vendors

  • Vendors like Candiru, Cy4Gate, Negg Group, Variston supply governments with spyware kits. Google TAG flagged small vendors responsible for 35 of 72 hacking tools targeting unpatched Google products from mid‑2014 to 2023.

Regional case—NoviSpy in Serbia

  • Amnesty International revealed Serbian authorities used Cellebrite tools to unlock activists’ phones and install homegrown spyware “NoviSpy”, which exported contacts and screenshots to government servers.

Mobile Android spyware “LianSpy”

  • It targets Android users in Russia. It hides on the home screen, records screen data, requires root permissions, and disguises itself as a legitimate app.

Conclusion

Spyware represents one of the most insidious threats in today’s digital landscape. It quietly harvests data, watches users, and often evades detection until it’s too late. Recent trends, including espionage-level tools like Pegasus, Daxin, Hermit, and mass targeting campaigns, make it clear that surveillance malware is evolving. Staying informed and proactive with spyware attacks surging worldwide is essential. Anyone can significantly reduce risk by combining strong cyber hygiene, reliable security tools, timely updates, and cautious behavior.  And if spyware does occur, malware scanners, manual cleaning, or whole device restoration can restore safety

FAQs

How is spyware different from a computer virus?

Spyware is a type of malware primarily designed for covert data collection and spying on users. A computer virus, by contrast, is self-replicating and intended to spread to other systems, often causing damage or corruption. While both are malicious software, spyware stealthily steals information rather than self-propagating.

Why do hackers use spyware instead of other malware types?

Spyware offers long‑term access to sensitive information (communications, credentials, behavior patterns) without immediately alerting the target. This stealth allows attackers to remain undetected for extended periods, whereas destructive malware (like ransomware) may draw attention quickly. Spyware is particularly favored in espionage, surveillance, or prolonged data theft campaigns.

What future threats could evolve from spyware technologies?

Deep-learning‑powered surveillance that adapts to behavior and prioritizes high‑value data.


Zero‑click attacks (like Pegasus or Triangulation) exploit unknown vulnerabilities for remote infection without user action.


Cross‑platform spy‑suites that combine PC, mobile, smart‑home, and IoT infections.


AI‑driven targeting delivers dynamic implants based on individual or organizational profiles.


Hardware‑level persistent implants, or firmware spyware, are resilient to software resets.

Can spyware steal my passwords or credit card info?

Yes, most spyware variants are designed to collect sensitive data: keyloggers capture credentials, screen capture, or app data harvesting (e.g., messaging and banking apps). Government‑grade spyware like Pegasus has been shown to harvest messages, passwords, contacts, browsing history, location, and more.

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About The Author

Bisma Farrukh

Bisma is a seasoned writer passionate about topics like cybersecurity, privacy and data breach issues. She has been working in VPN industry for more than 5 years now and loves to talk about security issues. She loves to explore the books and travel guides in her leisure time.

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