What Is Adware & How To Remove It?

Most people have encountered adware—you get onto a website with the intent to fact check your friend in the heat of a debate, search funny cat memes, or purchase the latest pair of shoes you’ve been dying to buy. But instead, you’re bombarded with pop-ups encouraging you to install software updates, and browser notifications you’ve never seen before.

These are just a few examples of what adware is and how it affects your everyday online experience. The following guide gives an in-depth explanation of what adware is, how to get rid of adware, and how to protect yourself from it.

What is adware?

The term "adware" refers to a type of software that serves you deceptive, shady, or simply annoying advertisements. Adware may show up on your device with your knowledge (typically these are free, legitimate apps funded through ads) or without your knowledge (most likely malicious). Adware is designed to advertise, but also often to damage and disrupt a system.

The malicious type of adware is very different from legitimate online advertising. Granted, some software applications push out annoying advertisements for actual businesses selling real products. These ads are typically designed into the software by an experienced developer and show up on webpages or apps.

However, malicious adware does not show ads in the same way legitimate advertising does. When infected by it, you might see new windows or tabs open, get spammed by random popups, notice differences in your home page or a new default search engine. Where legitimate ads display on a webpage or application, adware often shows up in places you wouldn’t expect it.

The entire purpose of adware is to make a pretty penny. Every time the user clicks on one of the ads, the company makes money.

How to determine if you have adware installed on your computer

Though adware sneakily finds its way onto computers, and even your mobile devices, there are signs to watch out for which will determine if your device is affected.

Below are only a few telltale signs to watch out for in determining if adware is on your device.

The homepage of your web browser changes without your acknowledgment.
Your selected web browser runs at an abnormally slow speed.
Your device installs unwanted applications without your permission.
Advertisements show up in unexpected places.
Links redirect you to unknown or unwanted sources.
Your browser all of a sudden has new extensions, toolbars and plugins.
Frequented websites on your computer do not display normally.
Your web browser unexpectedly crashes.

Types of adware

All adware is annoying, but not all of it is harmful. Along those lines, we can separate legal and illegal adware.

Legal adware

The legitimate type of adware is usually no more than a model of funding. These are free apps, which can remain free by serving you ads or collecting marketing data about you.

While annoying, this type of adware is common and usually harmless. Many respected businesses use ads to sustainably deliver a product to more people.

Illegal adware

On the other side of the coin we have malicious adware, which comes in many shapes and sizes:

At the relatively benign end, we have adware that aggressively feeds you advertising popups, hoping to maximize profits. These ads can drive you mad and significantly weigh on your system performance. Typically, however, that's where the issues end.
On the dangerous end is adware that will install software without your consent, hijack your browser, and even open the door for more malware. Aside from being a pain, this type of adware can seriously harm your cybersecurity.

What does adware do to your computer?

As stated above, adware can be legitimate. However, the malicious type of adware will have negative long-term effects on your computer or mobile device if not removed. Apart from annoying you with ads, adware slows down your device, sometimes to the point of being unusable. It may also affect your browser by installing unwanted add-ons, changing the homepage, etc.

Adware may also lead to more serious infections, for example, due to redirecting you to malicious websites. It may also contain a more serious infection as part of the adware package - you're only seeing the ads, but there are worse things going on in the background. For example, RelevantKnowledge collects personal information about you.

Examples of adware

Adware most often shows up on your device as displayed advertisements, banners, pop-up windows, and large, auto-play commercials in your web browser. The more aggressive type of adware is a lot rarer nowadays than it used to be. Here are some of the more famous adware examples from history:

Gator. Rampant in the early naughties, Gator would come together with widespread free programs and change all online ads with Gator ads. Not content with this outrageous feat, the adware would also collect lots of sensitive user data, including financial details.

Fireball. A relatively new adware example, this browser hijacker gained notoriety following a 2017 study, which claimed that it has infected approx. 250 million computers worldwide. Fireball floods you with ads, changes your default search engine to a fake one, and prevents you from modifying your browser settings.

DollarRevenue. One of the originals - around 2007, this nasty adware had infected 20+ million users, tracking searches and allegedly forming a botnet.

How do I get adware?

Adware typically finds its way onto your computer bundled with a new program. However, it can infect your computer in a number of other ways - malicious links, infected email attachments, USB drives, etc.

So the best way to prevent your device from getting adware is to avoid downloading questionable programs or clicking suspicious links. Another great rule of thumb is to avoid illegal activities on the internet - adware is a lot more prevalent in the shadier parts of the internet.

How to remove adware from your device?

Though blocking specific scripts within your browser might remove some problems, adware is typically written using programming languages that are also used by legitimate services on your device. Getting rid of those scripts would also affect the way your computer functions as a whole. Therefore, its typically better to find an alternative solution to removing scripts.

Typically, the best first steps are to back up your files regularly. In addition, download a legitimate cybersecurity software to notify you of potential issues. The process to removing adware on your device depends slightly on the type of device you own though. For more detailed information about how to remove adware from PC, Mac, Android and iOS devices, read below.

Removing adware from a PC or Mac

On a PC or Mac, adware is removed in the same way that viruses, spyware, and trojans are removed. The easiest way to do this is to use an antivirus removal tool which will review your device for mischievous code and remove it from your computer. For some of the best antivirus options, check out best antivirus list for 2024.

If the antivirus doesn't help, you may have to perform a full wipe of your device. Here's how you do it:

Backup your files.
Use a clean computer to create a bootable drive.
1. On Windows, use Microsoft’s USB/DVD Download Tool.
2. On Mac, hold the Command and R keys to boot from Recovery.
Boot from the USB drive (or another type of bootable drive).
Format (wipe) your hard drive and reinstall your OS.
Install a strong antivirus to scan your backup files - you don't want to get reinfected after all that work!Relevant reading for Mac users: How to reset your Mac to factory settings

Removing adware from an Android or iOS device

Adware can also affect your mobile device. One of the quickest fixes on an Android or iPhone is to remove recently downloaded apps from your device, on the chance that malicious adware found its way onto your phone via an app you've installed.

To do this, visit your app store, locate the application, clear the data and cache, and then uninstall the app. However, if you’re not sure which app is causing the problem, deleting all recently downloading apps might be the best solution. After following these steps, restart your phone to see if the adware has been removed.

How do I protect myself from adware?

Adware should be treated as seriously as any other malware. Therefore, taking the steps to prevent an adware infection is essential.

The first thing you can do is install a trustworthy antivirus program on your device. Keep it updated and always running in the background. Whenever you have suspicions that your device isn't acting right - run a scan immediately.

Secondly, browse securely using an ad-blocker/script blocker add-on. A few good choices are NoScript, Ghostery, and uBlock Origin. These browser extensions will greatly decrease your chances of getting infected in the first place.

Most importantly, however, you should be aware of the threats and browse carefully. Think twice the next time you plan to install software onto your device—especially if the software is free. Read the fine print and try to understand exactly what the device is going to do to your computer once installed. It is also best practice to avoid installing apps anywhere but from your computer’s app store. Regardless of where the app is downloaded though, always look into the details of the app prior to downloading it. You’d be surprised how many applications hide shady malware in their code.

Additionally, avoid shady websites, illegally downloaded content, and be suspicious of links on unfamiliar websites and emails. Being careful is the absolute best way to stay safe in a perilous digital world.