Request to Unknown Public DNS Server

To help secure the network, workstations are often configured to communicate with approved DNS servers. DNS-based attacks include redirecting traffic to malicious domains or beaconing to a command-and-control server through a DNS tunnel. Misconfigured clients, mobile devices, or guest devices on your network might communicate with unknown public DNS servers. The impact to a business can be low, but this activity should be examined before it enables critical and costly attacks.