What Is Spyware?

Spyware is a type of malicious software designed to secretly monitor a device and collect information without the user’s knowledge or consent.

Spyware is a category of software that is installed on a computer, phone, or tablet to observe user activity and collect data in a concealed way, typically without clear notice or meaningful consent. Its core purpose is surveillance: it records information such as what you type, which apps and websites you use, who you communicate with, where the device is located, and details about the device itself (like identifiers, configuration, and sometimes files or photos).

Spyware usually operates persistently in the background and transmits the collected data to an operator through the internet, often using techniques that make it blend in with normal system processes.

Types of Spyware

Let’s go through types of spyware in more detail:

Type of spyware	What it does	Typical data collected	How it usually gets on a device	Common signs
Adware (spyware-like)	Tracks behavior to build an ad profile and push targeted ads; may inject ads into pages/apps.	Browsing history, searches, ad clicks, device identifiers.	Bundled with “free” software, shady browser extensions, fake updates.	New toolbars/extensions, pop-ups, homepage/search engine changes.
Tracking cookies and web trackers	Follows users across sites/apps to measure behavior; not always “malware,” but can be privacy-invasive.	Pages visited, clicks, session IDs, device/browser fingerprinting data.	Loaded by websites, embedded scripts, third-party SDKs in apps.	Hard to notice; increased targeted ads, persistent logins/identifiers.
Keyloggers	Records keystrokes and sometimes clipboard data to steal credentials and messages.	Passwords, emails, chats, form inputs, clipboard contents.	Trojans, malicious attachments, cracked software, compromised installers.	Unusual CPU usage, security alerts, account logins from new locations.
Browser hijackers	Alters browser settings to redirect traffic and capture search/browsing behavior.	Search queries, visited URLs, clicks, sometimes credentials via fake pages.	Bundled installers, malicious extensions, fake codec/plugin prompts.	Search redirects, new default search engine, unwanted extensions reappearing.
Trojans with spyware features	A “legit-looking” app that installs a hidden payload to spy, steal, and persist.	Credentials, messages, files, screenshots, device info.	Phishing, pirated apps, fake “utility” apps, supply-chain compromises.	Random permission prompts, unknown apps/services, abnormal network traffic.
Info-stealers	Specialized malware built to extract stored secrets quickly.	Browser-saved passwords, cookies/session tokens, crypto wallets, autofill, system data.	Malicious downloads, cracked software, infected ads, phishing installers.	Accounts taken over despite “no password change,” sudden lockouts, fraud.
Mobile “spy apps”/stalkerware	Monitors a phone’s activity; often marketed for “monitoring,” but frequently abused.	Calls/SMS, chats, GPS location, photos, mic/camera access, app activity.	Installed with physical access; abuse of accessibility/admin/MDM permissions.	Battery drain, device overheating, unfamiliar admin/accessibility settings.
Remote Access Trojans (RATs)	Gives an attacker control over the device plus surveillance capabilities.	Screen view, files, mic/camera, keystrokes, credentials.	Phishing attachments, malicious installers, exploited vulnerabilities.	Webcam/mic activation, new remote services, unexplained admin tools.
System monitors/“dual-use” tools abused as spyware	Legitimate IT tools used improperly to watch users.	Activity logs, screenshots, process/app usage, network data.	Misuse by insiders; installed via enterprise management tooling.	New monitoring agents, management profiles, policy changes on the device.

Spyware Examples

Spyware examples illustrate how different variants operate in practice and what they are typically used for. They include:

Keyloggers. A common spyware example designed to capture everything a user types on a keyboard. They are often used to steal login credentials, credit card numbers, and private messages, and they usually run silently in the background after being installed through phishing emails or infected downloads.
Browser hijackers. These programs modify browser settings to redirect users to specific websites, inject ads, and track search queries and browsing habits. While they may appear less harmful, they significantly reduce privacy and can expose users to further malware.
Info-stealer malware. A more aggressive form of spyware that focuses on extracting stored data from a system in a short time. It commonly targets saved browser passwords, authentication cookies, crypto wallets, and autofill data, enabling attackers to take over accounts even without knowing the original passwords.
Mobile spy apps (stalkerware). They can monitor calls, messages, location, and app activity, and are frequently installed through physical access to the device. Although sometimes marketed for parental or employee monitoring, they are widely abused for unauthorized surveillance.
Remote access trojans (RATs). Represent advanced spyware that provides attackers with ongoing remote control of a device. In addition to spying on user activity, RATs can activate cameras and microphones, browse files, and execute commands, making them particularly dangerous in targeted attacks.

How Does Spyware Work?

Spyware works by getting onto a device, gaining the access it needs, quietly monitoring activity or collecting data, and then sending that information to whoever controls it. While details vary by type, most spyware follows a similar lifecycle:

Delivery and installation. Spyware arrives through a bundled installer, a malicious link or attachment, a trojanized app, a fake update, or an exploited vulnerability. This step’s goal is simply to land on the device and create an initial foothold.
Permission and privilege acquisition. After it’s on the system, spyware tries to get the access it needs to read data and monitor activity. On phones, that often means persuading the user to grant permissions (accessibility, device Admin, screen recording, location). On computers, it may attempt privilege escalation or leverage the rights of the current user. This step enables deeper visibility into the device.
Persistence setup. Next, spyware makes sure it survives reboots and keeps running over time. It may add itself to startup items, scheduled tasks, background services, or configuration profiles. The goal here is continuous collection rather than a one-time grab.
Stealth and evasion. With persistence in place, spyware reduces its chances of being noticed. It may hide its process, mimic legitimate names, limit resource usage, delay activity, or detect virtual/analysis environments. This step helps it operate longer without being removed.
Monitoring and data collection. Spyware then performs its main job, which is capturing information. Depending on the variant, it may log keystrokes, track browsing and searches, read messages, take screenshots, pull stored passwords and cookies, record location, or enumerate files and device identifiers. This step produces the “payload” data the attacker wants.
Packaging and exfiltration. Collected data is organized and sent out, usually to a command-and-control (C2) server or a third-party endpoint. Spyware often encrypts or compresses the data, and may transmit in small bursts to blend into normal traffic. This step moves sensitive information off the device.
Command updates and expansion. Finally, many spyware strains keep a channel open to receive instructions, changing what data is collected, deploying additional malware, or spreading to other accounts/devices. This step keeps the operation adaptable and can increase impact over time.

What Problems Does Spyware Cause?

Spyware causes problems by weakening privacy, compromising security, and degrading how a device behaves. At the personal level, it exposes sensitive information such as passwords, messages, photos, location history, and browsing activity, which can then be used for stalking, blackmail, or identity theft.

From a security standpoint, spyware often leads to account takeovers and financial fraud, especially when it steals login credentials or session cookies that let attackers access email, banking, and work tools.

Spyware also creates operational and performance issues. Because it runs in the background and communicates with external servers, it drains battery, increases data usage, slows down the device, and causes crashes or overheating. Some spyware changes browser settings or injects ads, which leads to constant redirects, intrusive pop-ups, and higher exposure to malicious sites.

In business environments, spyware can leak confidential documents, customer data, and internal credentials, increasing the risk of ransomware, regulatory penalties, and long-term reputational damage.

Who Typically Uses Spyware?

Spyware is used by different groups for very different reasons, ranging from profit-driven cybercrime to unauthorized personal surveillance. The intent and impact depend heavily on who is operating it. Here is who uses it:

Cybercriminals use spyware to steal credentials, financial information, and personal data that can be sold or used directly for fraud. Their goal is usually large-scale data harvesting, account takeovers, or preparing victims for further attacks such as ransomware.
Stalkers and abusive individuals deploy spyware, often in the form of mobile spy apps or stalkerware, to monitor a specific person. They may track messages, calls, location, and online activity to control, intimidate, or surveil someone without their consent.
Advertising and data brokers use spyware-like technologies to collect detailed behavioral data for profiling and targeted advertising. While some operate in legal gray areas rather than outright illegality, their tracking can still be highly invasive and opaque to users.
Insiders or malicious employees may use spyware to monitor coworkers or exfiltrate company data. This typically involves abusing legitimate access or installing monitoring tools without authorization, leading to internal data leaks and security breaches.
State-sponsored or intelligence actors use advanced spyware for targeted surveillance, espionage, or intelligence gathering. These operations are usually highly sophisticated, aimed at specific individuals or organizations, and designed to remain hidden for long periods.

How to Prevent Spyware?

Preventing spyware focuses on reducing exposure, limiting what software can do on your devices, and detecting threats early. While no single step is foolproof, combining the measures below significantly lowers the risk of infection. Here is what to do:

Keep operating systems and apps updated. Security updates patch known vulnerabilities that spyware commonly exploits. Regular updates close off easy entry points and reduce the chance of silent installation.
Install software only from trusted sources. Download apps, browser extensions, and updates from official stores or verified vendors. Avoid cracked software, unofficial mirrors, and pop-ups claiming you need an urgent update.
Use reputable security software. Antivirus and anti-malware tools can detect and block spyware during installation or while it is running. Keep real-time protection enabled and run periodic scans.
Review app permissions carefully. Pay attention to what access an app requests, especially on mobile devices. Be cautious with permissions like accessibility, device admin, screen recording, microphone, camera, and location, as these can be abused for spying.
Be cautious with links and attachments. Phishing emails, messages, and ads are common spyware delivery methods. Avoid clicking unknown links or opening attachments unless you can verify the sender and context.
Secure accounts and devices. Use strong, unique passwords and enable multi-factor authentication where possible. This limits damage if spyware does manage to capture some credentials.
Monitor devices for unusual behavior. Watch for signs like sudden battery drain, increased data usage, unexplained slowdowns, or new apps and settings you don’t recognize. Early detection makes removal easier and reduces data loss.

How Do I Know if I Have Spyware?

You can’t always see spyware directly, but it often leaves behind warning signs in how your device behaves. Knowing what to look for helps you catch an infection early and limit potential damage:

Notice unusual device behavior. Spyware commonly causes slow performance, frequent crashes, overheating, or sudden battery drain because it runs continuously in the background.
Watch for increased data or network usage. Many spyware programs regularly send collected data to external servers. Unexpected spikes in mobile data or network traffic can be a red flag.
Check for unfamiliar apps or processes. Look for apps, browser extensions, background services, or system processes you don’t remember installing, especially those with generic or misleading names.
Review permissions and system settings. Spyware often relies on powerful permissions such as accessibility, device admin, screen recording, or full disk access. Permissions enabled for apps you don’t trust or recognize are a strong warning sign.
Pay attention to browser changes. Redirects, a changed homepage or search engine, new toolbars, or persistent pop-ups can indicate spyware or browser hijackers.
Look for account security issues. Unexpected password resets, login alerts from new locations, or accounts being accessed without your action may mean spyware is capturing credentials or session data.
Run a security scan. Using reputable antivirus or anti-spyware software to scan your device can help confirm suspicions and identify hidden threats that aren’t obvious through symptoms alone.

How to Remove Spyware?

Removing spyware requires a careful approach to stop the surveillance, clean the device, and prevent reinfection. Acting methodically is important, especially if sensitive data may be involved. Here is how to remove it:

Disconnect from the internet. Take the device offline to immediately stop spyware from sending data out or receiving new commands. This limits further data exposure while you work on removal.
Identify suspicious apps or programs. Check installed applications, browser extensions, background services, and startup items for anything unfamiliar or unnecessary. Spyware often hides behind generic or misleading names.
Remove suspicious software manually. Uninstall unknown or unwanted apps and extensions using the system’s normal removal process. On mobile devices, also revoke dangerous permissions such as accessibility, device admin, or screen recording before uninstalling.
Run a full security scan. Use reputable antivirus or anti-spyware software to perform a deep scan. This helps detect hidden components, leftover files, or spyware that is not visible through normal system menus.
Check system and browser settings. Reset browser settings, review startup configurations, and remove unknown profiles or management tools. This step ensures spyware has not altered how the device launches or connects online.
Update the operating system and apps. Install the latest updates to patch vulnerabilities that spyware may have exploited. This reduces the chance of the same threat returning.
Change passwords after cleanup. Once the device is clean, change passwords for important accounts from a secure device and enable multi-factor authentication. This protects accounts that may have been compromised while spyware was active.

Spyware FAQ

Here are the answers to the most commonly asked questions about spyware.

Is Spyware a Virus or Not?

Spyware is not a virus, but it is a type of malware. A virus is specifically designed to replicate itself and spread by infecting other files or systems, while spyware’s primary purpose is to secretly monitor activity and collect data. Although spyware can spread through deceptive installers or malicious links, it does not self-replicate in the way a true virus does, which is why it is classified separately even though both pose serious security risks.

Can Spyware Watch You?

Yes, spyware can watch you, depending on how advanced it is and what permissions it has. Some spyware is limited to tracking browsing activity or collecting stored data, but more intrusive variants can actively monitor behavior in real time. This may include recording keystrokes, reading messages, tracking location, taking screenshots, and, in severe cases, accessing the microphone or camera. On smartphones, spyware that abuses accessibility, device admin, or similar high-level permissions can provide near-continuous surveillance.

While not all spyware has full “watching” capabilities, any form of unauthorized monitoring represents a serious invasion of privacy and security.

What Are the Legal Implications of Using Spyware?

The legal implications of using spyware are serious and vary by country, but unauthorized use is illegal in most jurisdictions. Installing or operating spyware without clear, informed consent typically violates privacy, wiretapping, computer misuse, and data-protection laws. This can lead to criminal charges, civil lawsuits, fines, and even imprisonment, especially when spyware is used to intercept communications, steal credentials, or track someone’s location.

Even in workplace or parental contexts, legality depends on strict conditions such as transparency, proportionality, and lawful purpose. Employers usually must notify employees and limit monitoring to business needs, while parents’ rights are often restricted by a child’s age and local privacy laws. Misuse, such as spying on a partner, coworker, or private individual without consent, is commonly prosecuted and may also trigger additional charges related to harassment, stalking, or domestic abuse.