What Is Adware?

Date First Published: 4th May 2023

Topic: Cybersecurity

Subtopic: Threats To Systems, Data & Information

Article Type: Computer Terms & Definitions

Difficulty: Medium

Difficulty Level: 4/10

CONTENTS

How Does Adware Spread?
Legitimate Adware
Signs Of Adware

Learn more about what spyware is in this article.

Adware is a type of malware that displays unwanted ads on the victim's computer, often in their web browser, to generate revenue for the creator. Adware may capture information about the victim, like the pages they previously browsed, to target ads towards them and increase the chances of clicks. Adware can sometimes sell the victim's information and browsing habits to third parties so that they can target them for even more ads.

Some types of adware may simply be an annoyance and not do anything harmful. On the other hand, other types of adware can be a security risk as they may try to install keyloggers and spyware onto your computer.

How Does Adware Spread?

Adware often spreads through bundled downloads and malicious websites. When you install a program, you may also be agreeing to install another program, like an adware program that displays unwanted ads in your web browser. Since it is common for users to click Next or Okay without reading the agreement, adware can install on user's computer without their knowledge. Some authors may sign up for an adware service so that they can make money from all the unwanted ads displayed on the victim's computer without their permission.

Adware is designed to remain hidden on the victim's device and silently run in the background, so it doesn't usually harm any files or applications. However, antiviruses can detect and remove adware from your computer, as long as they are up to date. You can protect your computer against adware by not downloading and running unknown files, using a popup blocker to prevent unexpected windows from opening, reading reviews to ensure that applications are legitimate, and being careful when installing free software as you may also be agreeing to install an adware program.

Legitimate Adware

Adware is not always malicious. It can also be legitimate as some free software is supported by ads. The ads will only display inside the software and not in other applications. The ads help keep the software free and users consent to the ads before they install the software. Users that want to remove ads can buy the paid version.

Signs Of Adware

The following signs indicate that your computer has an adware program installed:

Your web browser keeps redirecting to scam sites or sites filled with ads that you were not expecting.
Ads appear in unusual places, like on Windows system tools.
Your web browser homepage has unexpectedly changed without your permission.
Your computer is running very slow, constantly crashing, or freezing.
New toolbars, extensions, or add-ons have unexpectedly appeared in your web browser without your permission.
Constant popup ads that unexpectedly appear in your web browser over and over again.
Webpages that you usually visit are not loading properly.
Web searches redirect to sites other than expected.
You keep receiving fake messages about apps or viruses on your computer (e.g. Virus detected. Clean your PC now.)