DNSFilter

DNSFilter blocks dangerous and unwanted websites at the DNS lookup, the step where a device asks which server a domain name points to. If the domain is known for malware or phishing, or falls into a category you have blocked, the lookup is refused and the user sees a block page instead of the site.

It classifies domains with machine learning that reads new sites as they appear, so newly registered phishing domains can be caught before they land on a block list. You can point an office router or firewall at its resolvers, or install a roaming client on laptops so filtering follows staff home and onto public Wi-Fi.

It is sold directly and through MSPs, with a multi-tenant console for managing many clients. DNS filtering is a cheap first layer, and it can't see inside traffic to a site that is allowed. Check how the roaming client handles VPNs, and how staff can ask to unblock a site that was wrongly flagged.