What is spyware? 5 ways to protect your computer from being infected

• Spyware is a type of malware that secretly monitors you, steals sensitive information from your PC, and sends it to third parties without your knowledge.
• Some spyware might track your behavior online while others can record passwords or even log your keystrokes.
• You can avoid spyware by following common safe computing practices that are designed to protect you from all forms of malware.

Spyware is a common variety of malware that, as its name implies, is designed to spy on you. It's usually software hidden on your computer or masquerades as something benign and gathers certain information that it sends to other parties without your knowledge or consent.

Often, people describe legitimate and mainstream software as spyware — for example, certain social media platforms like Facebook often get this label — but that's a misuse of the term. Real spyware is much more dangerous.

What you need to know about spyware

There are many varieties of spyware, and each one has its own set of behaviors. For example, some spyware is installed in the same way as other malware: by clicking infected links in email or on websites or by opening an email file attachment that has a malicious spyware payload.

But spyware can also be "bundled" with other software you believe is legitimate. For example, low-quality free software on the internet might have undisclosed spyware components that install along with the primary app.

Here are the main kinds of spyware most people are likely to encounter:

• Tracking cookies. This is software that can follow your activities online and record in detail all the sites you visit.
• Trojan spyware. Taking its name from the mythical Trojan Horse, this kind of spyware masquerades as legitimate software — perhaps a Java update or Flash Player — but steals sensitive data from your computer.
• Adware. This software's purpose is to serve ads to you, often (but not always) based on your behavior and browsing history.
• Keyloggers. This kind of spyware can record all your keystrokes, capturing a vast amount of information, including login credentials for secure websites.

How to avoid becoming infected with spyware

Spyware is insidious, but it's just another form of malware, and so if you're familiar with common precautions to avoid infection, these tips will serve you well against spyware as well.

Avoid installing free software from questionable sources

There are many tools online that claim to perform tasks that you can't generally do with Windows or mainstream applications. You might need to create or fill out a PDF, for example, and lack the right commercial tool to do that. Or you need to read an obscure file format for a program you don't own. A Google search might turn up free apps offering to do exactly those things. While it's certainly possible you might find legitimate tools to perform these tasks, many of the free options may be bundled with spyware. You're better off purchasing a tool known to be reputable than taking a chance with the alternative.

Use anti-malware software

Your computer should be protected by some form of anti-malware or antivirus software, and most modern programs will protect you from common spyware. At a minimum, use the security software built into Windows, though you can use third-party tools as well. Make sure your software stays current with regular updates.

Keep your computer updated

Keep your computer itself up to date with the latest Windows software and security updates, or take these steps to troubleshoot if your computer won't update.

Don't click anything you don't trust

Follow the tried-and-true advice to never click anything you don't fully trust. That includes both links and attachments in email — if you don't know the sender, or if the email's legitimacy seems questionable — don't open anything inside it. The same is true for following links on websites of questionable quality.

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