Browser and DNS filtering

Browser and DNS filtering tools try to stop staff from reaching dangerous websites at all. A phishing link in an email, a fake download page in search results or a site serving malware is blocked before the page loads, which catches some attacks that email filters and endpoint agents miss.

DNS filtering works at the very first step of visiting a site. Before a browser loads a page, the device asks a DNS resolver which address a domain name points to. A filtering resolver checks the name against threat intelligence and site categories, and refuses to answer for known malware, phishing or blocked categories. It is easy to roll out: point the office router or firewall at the filtering service, and install a small client on laptops so protection follows staff home and onto public Wi-Fi. Because it works for every app on the device, it also blocks malware trying to contact its control servers.

The AI here is mostly classification. New phishing domains appear constantly and are often used for only a few hours. Tools in this category use machine learning to read and classify new domains as they appear, so a site can be blocked before it reaches a public block list.

Browser security tools work inside the browser itself, where most work now happens. Some are full enterprise browsers that the company manages. Others are extensions added to Chrome or Edge. They can detect fake login pages, block risky extensions, control downloads and copy and paste, and limit what staff can paste into AI chat tools, which matters if people are putting customer data into public chatbots. Isolation tools open pages in a remote environment so code from the site never runs on the device.