There are already AI for preemptively blocking DNS records that look suspicious, a few of the DNS services I'm aware that OP could (and should) set up for his f

There are already AI for preemptively blocking DNS records that look suspicious, a few of the DNS services I'm aware that OP could (and should) set up for his father are NextDNS [0] or AdGuard DNS [1][2]. Apart from dynamic detection using AI and heuristics both of these services also ship with DNS-level blacklists, you may also blacklist or whitelist specific websites if any lists generate issues on safe websites. [0]: https://nextdns.io/ https://nextdns.io/ [1]: https://adguard.com/ https://adguard.com/ [2]: https://adguard-dns.io/en/welcome.html https://adguard-dns.io/en/welcome.html