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What is spyware and how to remove it from your computer

A computer that has become infected with spyware will expose its user to severe privacy and security risks. Spyware is extremely good at hiding on a device surreptitiously, which means it often goes unnoticed by its victim.

As a result, spyware can allow cybercriminals to log keystrokes, steal passwords, harvest Personally Identifiable Information for engaging in identity theft, or to steal financial information to engage in fraud. With so many potential risks involved, it is vital to understand how to detect and remove Spyware – if you don't want to become another hacking statistic.

In this guide, we will describe the different types of spyware you need to be aware of. And we will explain how to detect spyware on your devices so that you can remove it once and for all.

What is spyware?

Spyware is a category of malware that remains concealed on a device while spying on its user to steal data. Spyware can function in a variety of different ways:

  • Attached to your operating system to run in the background as a memory-resident program.
  • Disguised as a file that is necessary for your Operating System.
  • Concealed in an app downloaded from unofficial third-party app stores.
  • Installed via a dodgy download on a torrent site.

How do you become infected with spyware?

Spyware can make its way onto a victim's machine in a variety of ways.

Phishing and malicious downloads

Phishing emails and messages are a common attack vector that can infect you either with malicious attachments or via a link that takes you to a malicious website. Thus, the vast majority of the time people become infected with applications due to their own actions, and the software they opt to install. 

Direct infections

It is possible to become infected by someone with physical access to your computer or mobile device. It is for this reason that it is so important to lock computers and mobile devices with a password and a screen lock. Perpetrators install spyware on devices to snoop on family members, romantic partners, friends, and work colleagues. 

Malicious and cloned websites

Hackers often create genuine-looking hoax websites designed to look like they belong to a genuine organization. These malicious websites may contain links and pop-ups that cause victims to download spyware either onto their computer or browser.

Genuine applications and 'legitimate' snooping

Reports have emerged of government agencies infecting unsuspecting citizens with spyware via iTunes. In addition, manufacturers are known to install bloatware on mobile phones used to monitor device owners. Critics and privacy advocates consider this unauthorized spyware.

People even become infected with Spyware via the legitimate programs and apps they purchase and install (the developer usually mentions the purpose of that spyware in the small print of the privacy policy. It is usually there to allow the company to harvest data for marketing purposes)

What are the different types of spyware?

Different types of spyware do different tasks, which means they may spy in different ways. Mobile spyware may track your geo-location, for example. Other types may spy on you via your camera or microphone. Some forms of Spyware are more dangerous than others – but they are all worth knowing about:


These allow a hacker to gain privileged access to your device and all its functions it can allow the hacker to deliver secondary payloads from a Command and Control (CnC) server to cause further damage. There are different forms of trojans, such as Banking Trojans, which are designed to leverage insecurities in browsers to steal banking information and logins. They may also automatically modify transactions to route money to an account held by the hacker.

Password stealers

These are designed to harvest login credentials and passwords from infected computers to send them back to a CnC server belonging to the hacker. 

Information scanners

These scan a machine for valuable personal information such as credit card numbers and email addresses. They are often leveraged to steal emails in order to send phishing emails to all your contacts in order to infect them with spyware too.


This spyware logs your keystrokes, allowing hackers to lift passwords and logins, and any other sensitive personal information that you divulge while typing on your machine (such as payment information).

Mobile spyware

Tracks your GPS location call logs, contact lists, app data, photo roll, videos, and documents stored on your device.

Camera and microphone spyware

Can be used to snoop on you in real-time, to take videos of you, to record your conversations, and even to run facial recognition and harvest biometric information. 

Cookies and trackers

Cookies are extremely common on websites and apps, which have built-in functions and permissions designed to harvest your data. Since they send your data to advertisers and snoop on you and your device, we can consider them a type of spyware. 

How to avoid becoming infected with spyware

The good news is that there are things you can do to prevent yourself from becoming infected with malware. Following the rules below will massively improve your chances of avoiding an infection:

How to identify a spyware infection

If your computer or mobile device has become infected with spyware, it is possible that this will affect your device's performance. As a result, there are things you can expect when detecting whether an infection has occurred:

  • Unexpected adverts and pop-ups appearing in your browser, apps, or the programs you use. 
  • Unusual levels of battery drain and high temperatures (mobile devices and laptops).
  • Slow loading programs, sluggishness online, and unusual device crashes.
  • Unusual toolbars, home pages, or search engines you don't remember installing or setting up.
  • Problems logging into secure online portals requiring regular multiple attempts (may mean that you are being phished via fake login portals)
  • A noticeable increase in data usage or bandwidth use. 
  • Antivirus and safety programs such as Windows Defender working unusually or have become disabled without your permission.
  • Unusual apps that you don't remember installing have appeared on your device.
  • Check Task Manager (Windows) or Activity Monitor (macOS) to see if unexpected programs are running in the background (bear in mind that spyware often conceals itself as a system file, which can make it hard to detect.)

How to remove spyware from your computer 

If you have noticed any of the symptoms above, and are suspicious you may have become infected with malware, it is essential that you do something about it as soon as possible. Below, we have included the best steps to take.

Use a removal program

The best bet is to use a spyware detection and removal program, and we strongly recommend that all internet users have malware installed that has active protection. Most good antiviruses nowadays have a malware detection and removal function that works in real-time. If you do not currently have an antivirus program, check out our best antivirus page for a list of recommendations or head over to our best free anti-spyware page for a list of the best services.

However, if you have noticed something unusual, it is important to check that your antivirus is still running and that it is up-to-date with the latest virus definitions. We also recommend that you run a deep scan, as you may have your antivirus setup to perform quick scans only.

If your antivirus is up to date and does not detect anything, then it is likely that you are not infected. However, you can opt to double-down by running another program such as Malwarebytes (which you can download and use for free). 

It is important to remember that there are tools on the market that advertise themselves as malware or spyware removal applications, but actually contain spyware themselves. This is why it is essential that you stick to one of the trustworthy antivirus recommendations in the link above.

Finally, it is important to note that Spyware is often stubborn and may have built-in functions designed to reinstall itself even after you remove it. For this reason, clear your internet cache to ensure that you do not suffer reinfection due to persistent trackers or cookies attached to your browser. Following that, run another scan to ensure that you are still clear (and run regular scans to ensure you do not suffer reinfection). 

Use a reliable firewall with outbound scanning

A firewall is designed to scan all your ports for incoming packets. This allows you to set up rules to ensure that no unwanted communication with your computer can occur.

By implementing a strong firewall, you can prevent hackers from sending data to your computer.

Default firewalls like the one that comes with Windows Defender only check incoming traffic. As a result, it is possible that spyware already on your computer could send data to a CnC server without being blocked. This is why some people prefer to install an antivirus program that comes with an advanced firewall (or a stand-alone advanced firewall program like Little Snitch). 

Advanced firewalls scan both incoming and outbound packets and alerts you and blocks any traffic that is being sent from a Trojan to servers controlled by hackers. This allows you to detect that you have spyware on your program and can prevent data from being stolen by those programs. 

Improve privacy with anti-tracking extensions

If you want to prevent online services from tracking you as you visit websites, then it is vital that you use extensions that prevent tracking. Adblockers and privacy extensions are an easy (and free) way to gain much more privacy online.

To find out more, check out our privacy extension reviews. In addition, check out our guide on how to gain added privacy on Firefox

We also recommend that you use a VPN service, as this will prevent the online services you use from tracking your IP address. VPNs are by far the best way to gain added privacy online and should be used alongside an antivirus program and browser extensions to prevent services, Wi-Fi providers, local network admins, and government from tracking your web visits. Check out our best VPN guide for a list of the best services in 2024. 

Written by: Ray Walsh

Digital privacy expert with 5 years experience testing and reviewing VPNs. He's been quoted in The Express, The Times, The Washington Post, The Register, CNET & many more. 


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