Ad Injection is the unauthorized addition of ads to a webpage, often by malware or browser extensions. Injected ads disrupt user experience and may harm the site’s reputation, as they are typically low-quality or irrelevant. Ad injection is considered a form of ad fraud.

Combating ad injection is crucial for maintaining a safe and trustworthy ad environment. Using verification tools and monitoring traffic can help detect and prevent unauthorized ads, ensuring the content users see is approved and relevant.