Browser plug-ins are software components that add functionality to a web browser, such as playing videos, displaying animations, etc. However, some browser plug-ins can also be malicious or compromised and cause unwanted pop-up advertising messages while browsing the internet. A malware scan may not be able to locate the source of the infection if it is hidden in a browser plug-in. Windows updates, DNS settings and certificate store are not likely sources of pop-up advertising messages. Verified Reference: https://www.comptia.org/blog/browser-security https://www.comptia.org/certifications/a