Dig Dug image - TryHackMe easy DNS server room

Solving Dig Dug – an Easy TryHackMe DNS Challenge

by

Complete and detailed writeup of Dig Dug – an easy TryHackMe DNS server room.

CTF Writeups & Bug Bounty » Try Hack Me » THM Challenges » Solving Dig Dug – an Easy TryHackMe DNS server

Link to the room on TryHackMe

Table of contents

Introduction – Dig Dug

From the TryHackMe description, we learn that:

  • The target is in fact a DNS server
  • We must use common DNS enumeration tools that are available on the attack box
  • We must retrieve the flag from a “special type of request for a givemetheflag.com domain“

Let’s see!

Getting the flag through DNS

First, let’s run nmap to confirm the DNS server is running on the default DNS port (53):

root@ip-10-80-180-122:~# nmap -sU -p 53 -sV 10.80.140.191
Starting Nmap 7.80 ( https://nmap.org ) at 2026-01-19 09:13 GMT
mass_dns: warning: Unable to open /etc/resolv.conf. Try using --system-dns or specify valid servers with --dns-servers
mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using --system-dns or specify valid servers with --dns-servers
Nmap scan report for 10.80.140.191
Host is up (0.00011s latency).

PORT   STATE SERVICE VERSION
53/udp open  mdns    DNS-based service discovery

nmap options:

  • -sU: UDP scan (DNS uses UDP to receive client requests)
  • -p 53: only scans port 53
  • -sV: tries to determine the version of detected services

Great, port 53 is indeed open and a DNS server is listening.

Let’s just do what we were told – send a request to this DNS server to resolve the givemetheflag.com domain.

For this matter, we’re going to use dig and the A record:

root@ip-10-80-180-122:~# dig @10.80.140.191 givemetheflag.com A +short
"flag{0767************************}"

dig options:

  • @10.80.140.191: tells dig to use the DNS server 10.80.140.191 to resolve the domain name
  • A: queries the A record (IPv4 address)
  • +short: only shows the answer, not the whole process

Well, it was very very simple.

The flag is the response to the most basic DNS request.

I’m almost disappointed…

Conclusion – Dig Dug a bit too simple?

Very short and easy room.

But it still serves as a great introduction to DNS and using dig, which is always tricky to use when we begin (at least it was for me).

But they could have chosen a less ordinary record to hide the flag…

READ MORE Try Hack Me WRITEUPS

Disclaimer

This article is provided for educational purposes only.

All techniques demonstrated were performed in a controlled lab environment.

Do not attempt to reproduce these actions on systems you do not own or have explicit authorization to test.

I do not encourage or take responsibility for any illegal use of the information provided.

Leave a Comment