Adware is software that displays unwanted advertisements on a user’s device, often to generate revenue for its operators. While some ad-supported applications are legitimate, malicious adware can be installed without clear consent, disrupt user activity, collect browsing data, and expose organizations to additional security risks.

Adware commonly spreads through bundled software downloads, deceptive installation prompts, compromised websites, or malicious advertising campaigns. Once installed, it may modify browser settings, inject advertisements into web pages, redirect searches, track online behavior, and communicate with external servers to deliver targeted content or collect information.

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Why adware matters

Although adware is often viewed as a nuisance, it can have serious business consequences. Adware consumes system resources, degrades performance, interrupts employee productivity, and may collect sensitive business or user data. In some cases, adware also serves as an entry point for more advanced threats, increasing the risk of malware infections, data exposure, and network compromise.

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Signs of an adware infection

Common indicators of adware include:

• Excessive pop-up advertisements
• Unexpected browser redirects
• Changes to homepage or search settings
• Slow device or browser performance
• Unauthorized browser extensions or toolbars
• Increased network activity from unknown sources

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How to prevent adware

Organizations can reduce adware risk by:

• Restricting software downloads to trusted sources
• Keeping browsers, operating systems, and applications up to date
• Using endpoint protection and anti-malware solutions
• Implementing DNS-layer security controls
• Blocking access to known malicious domains
• Training users to recognize deceptive downloads and advertisements

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How DigiCert can help

DigiCert UltraDDR helps organizations defend against adware and other web-based threats through protective DNS (PDNS) security. By identifying and blocking connections to known malicious domains, command-and-control infrastructure, and other high-risk destinations, UltraDDR helps prevent infections, reduce exposure to malicious content, and strengthen overall cyber resilience. Organizations gain greater visibility into DNS activity, enabling faster detection and response to emerging threats before they impact business operations.