What Is Adware? Learn How to Prevent and Remove It

The Neeva Team on 09/08/21

Adware may not seem as dangerous as other types of malware (malicious software), like ransomware or spyware, but it is far more common than any other type of malware—and it’s becoming even more prevalent. From 2018 to 2019, cybersecurity company Malwarebytes reported a 13% increase in consumer adware detections and a 463% increase in business adware detections, making adware its number-one malware category to watch.

What is adware?

Adware, also known as advertisement-supported software, is a type of software that displays ads. Adware can infect both desktop and mobile devices, including Macs, PCs, Androids, and iPhones. It sounds harmless enough, but some types of adware go to great lengths to turn your device into an advertising machine, such as:

  • Using deceptive means to make their way onto your device, such as pretending to be (or partnering with) a useful or reputable application.
  • Taking control of your device by redirecting browsing, changing your homepage, or subscribing to services on your behalf.
  • Infecting legitimate apps with malicious code, and forcing those apps to display advertisements as well.
  • Inundating your device with ads, which may slow device performance and eat up battery life and/or data.

Where does adware come from?

There are two main ways your device can become infected with adware.

  1. Infection by download. Most of the time, adware appears on your device because you downloaded it. Adware developers go to great lengths to trick you into downloading their software. They may pretend to be another popular app, like Fortnite, or claim to provide a useful function, like tracking packages. Or they may partner with a legitimate app, so that when you download the desired app, you’re also downloading adware—and the only way to know would be to read the fine print.
  2. Infection by exploit. Also known as a drive-by download, this less-common way of contracting adware involves visiting a compromised website. Code on the site will exploit weaknesses in your web browser to automatically download the unwanted adware.

What’s the difference between legitimate and malicious adware?

Plenty of popular apps and online services are supported by advertising. So how can you tell if you’re dealing with run-of-the-mill advertising or something potentially dangerous?

Legitimate advertising-supported apps will be transparent about the fact that they serve ads, and they should display ads only when you’re using that app. They may even offer an ad-free, paid version of the app. These apps are typically safe to use, and you’ll rarely see them described as “adware,” since advertising is secondary to the software’s other purpose.

Malicious adware isn’t transparent about its purpose, and it may sacrifice your privacy or your device’s functionality in the name of advertising. Adware programs range from so-called potentially unwanted programs (PUP), which may not be illegal but may be manipulative and annoying, to outright illicit software. Signs that an application might be malicious adware include:

  • Impersonating other apps. Adware often isn’t what it claims to be—it may be a free or fake version of a popular app, or it may claim to provide a utility that it does not in fact provide.
  • Violating users’ privacy. Adware will sometimes track your behavior, such as location, search, and/or browsing history, for the purpose of showing targeted ads or selling your information to third parties, not for app functionality.
  • Serving invisible ads. Some types of adware produce invisible ads, which can’t be seen by users, but still generate revenue for developers.
  • Performing unwanted tasks on your device, such as automatically clicking on ads, changing your preferences, or installing unwanted programs.

How to spot an adware infection

An adware infection can present as many different symptoms. If you’re using a desktop or laptop computer, you may notice things like:

  • Changes in your web browser homepage and/or search settings
  • Web pages not displaying correctly
  • Pop-up ads appear even when you’re not browsing the internet
  • Computer performs slower than usual and/or crashes
  • Internet speed is slower than usual
  • Searches are redirected
  • Ads appear out of context, or in places where you haven’t seen them before
  • New extensions or toolbars appear on your browser
  • New applications appear on your computer

The signs of a mobile adware infection are similar:

  • Phone performs slowly
  • Battery drains quickly
  • Increased size and quantity of ads
  • Ads appear in unusual places like your notifications screen, lock screen, and as full-screen pop-up ads
  • Apps appear that don’t remember downloading
  • Unexplained data usage

How to remove adware from an Android

If you believe your Android device may have been infected with adware:

  1. Back up your device. This is the first step in any troubleshooting process. This way, if something goes wrong, you’ll be able to revert your device to the way it was before. If you perform regular backups, one option is to simply restore your device to a backup from before you experienced the adware issue.
  2. Update your apps and operating system. Software developers are constantly updating their apps and operating systems to eliminate malware threats. Sometimes, simply updating your apps and operating system and restarting your device can solve the issue.
  3. Clear your browser’s cache and cookies. Occasionally, clearing the stored information on your browser can eliminate an adware issue. Here’s how to do this on Chrome for Android. (The process may vary for other browsers.)
  4. Start your phone in safe mode. Safe mode reboots your device, without third-party apps. How to do this will vary by device, so check your manufacturer’s website for details.
  5. Test the device. If your device now runs normally, you now know that the issue is a third-party app (or apps).
  6. Exit safe mode. Again, this process may vary by device, but usually consists of simply restarting your device (turning it off and then on again).
  7. Remove apps one by one. Delete suspicious third-party apps. If the problem is recent, you can start with your most recently downloaded app. After deleting each app, restart your phone and test it out. If the problem goes away, you’ve found the culprit! If not, keep deleting and restarting until you do. Once you’ve solved the problem, you can reinstall any innocent apps. (You may have to login again, so make sure you’re using a solid password manager, such as 1Password or LastPass, to make the process easier.)
  8. Call in the pros. If you have a persistent adware problem, you may consider downloading a legitimate adware removal tool or antivirus software such as Malwarebytes, Norton, or TotalAV. Some people also install ad blockers, which can sometimes block adware.

How to remove adware from an iOS mobile device

If you have an iPhone or iPad that may have been infected with adware:

  1. Back up your device.
  2. Update your apps and operating system. Software developers are constantly updating their apps and operating systems to eliminate malware threats. Sometimes, simply updating your apps and operating system and restarting your device can solve the issue.
  3. Clear your browser’s cache and cookies. Occasionally, clearing the stored information on your browser can eliminate an adware issue. If you use Safari, go to Settings > Safari, and tap Clear History and Website Data. While you’re at it, make sure you’ve enabled Block Pop-Ups and Fraudulent Website Warning are enabled. If you use another browser, the process may be different.
  4. Remove apps one by one. Delete suspicious third-party apps. If the problem is recent, you can start with your most recently downloaded app. After deleting each app, restart your device and test it out. If the problem goes away, you’ve found the culprit! If not, keep deleting and restarting until you do. Once you’ve solved the problem, you can reinstall any innocent apps. (You may have to login again, so make sure you’re using a solid password manager, such as 1Password or LastPass, to make the process easier.)
  5. Call in the pros. If you have a persistent adware problem, you may consider downloading a legitimate adware removal tool or antivirus software such as Malwarebytes, Norton, or TotalAV. Some people also install ad blockers, which can sometimes block adware.

How to remove adware from a computer

If your computer seems to have an adware infection:

  1. Back up your device.
  2. Update your applications and operating system. Software developers are constantly updating their apps and operating systems to eliminate malware threats. Sometimes, simply updating your applications and operating system and restarting your computer can solve the issue.
  3. Clear your browser’s cache and cookies. Occasionally, clearing the stored information on your browser can eliminate an adware issue.
  4. Remove unwanted browser extensions. While you’re on your browser, take a look at your browser extensions. Delete any extensions that seem suspicious, or that you don’t regularly use.
  5. Delete applications one by one. Delete suspicious third-party applications. If the problem is recent, you can start with your most recently downloaded applications. After deleting each application, restart your computer and test it out. If the problem goes away, you’ve found the culprit! If not, keep deleting and restarting until you do. Once you’ve solved the problem, you can reinstall any innocent apps. (You may have to login again, so make sure you’re using a solid password manager, such as 1Password or LastPass, to make the process easier.)
  6. Call in the pros. If you have a persistent adware problem, you may consider downloading a legitimate adware removal tool or antivirus software such as Malwarebytes, Norton, or TotalAV. Some people also install ad blockers, which can sometimes block adware.

6 ways to protect yourself from adware

Whether you’ve dealt with an adware infection in the past and want to protect yourself from future attacks, or you’ve never experienced adware and want to keep it that way, here are six things you can do to keep your device safe.

  1. Keep your software up to date. Software updates often help fix vulnerabilities and remove malware.
  2. Back up your device. Regularly backing up your device provides you with a quick fix for adware problems: When your device starts acting up, simply revert to a previous backup.
  3. Use your device’s official app store. Use the App Store for Apple devices, or Google Play for Androids, or download software directly from a trusted developer’s website. Although adware exists on those platforms, you’re even more likely to download adware when you visit an unofficial app store. If you use an Android device, make sure Google Play Protect is on, and only download apps that are Play Protect certified.
  4. Do your research. Before downloading an app, pause. Search for the developer’s name online, read reviews, and watch out for spelling mistakes. If anything seems fishy, stay away.
  5. Check permissions. Is a new app asking for unnecessary permissions? That can be a red flag that the app isn’t what it seems. Review permissions for previously downloaded apps and revoke permissions or delete anything that seems suspicious.
  6. Stay away from illegal activities. Illegal software, such as torrenting apps, is a common source of adware.


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