There are 3 repositories under dns-tunneling topic.
Surreptitiously exfiltrate data from the browser over DNS
Keylogging server and client that uses DNS tunneling/exfiltration to transmit keystrokes through firewalls.
ICMP and DNS tunneling via IPv4 and IPv6
Coyote is a standalone C# post-exploitation implant for maintaining access to compromised Windows infrastructure during red team engagements using DNS tunneling.
Deep Learning for Domain Name System
Here is an example which shows an idea how DNS tunneling can be implemented in Java.
proof of concept for a DNS tunneling client and server, for security education
Describes an architecture for DNS Tunneling detection at AWS cloud using ELK.
Deep Learning Based DNS Tunneling Detection and Blocking System
Detection of malware bot and botnet activities over DNS / Master's Thesis
DNS Incident Response