Cybersecurity

Adware

Definition

Adware is software that generates revenue for its developer by automatically generating online advertisements in the user interface of the software or on a screen presented to the user during the installation process. While some adware is harmless, it can also be a form of spyware that tracks user behavior without consent.

Why It Matters

Adware can be extremely annoying, degrading the user experience with unwanted pop-ups and ads. More malicious forms can compromise user privacy by tracking browsing habits and other personal information.

Contextual Example

A user installs a "free" browser toolbar, which then starts injecting extra banner ads and pop-ups onto every website they visit. This is adware.

Common Misunderstandings

  • Adware is often bundled with free software downloads.
  • While not as directly damaging as ransomware, it can be a gateway to other types of malware and a significant privacy risk.

Related Terms

Last Updated: December 18, 2025