Fun with “TXT records”
I recently moved my domains to a new domain registrar. Along with that, I had to modify some DNS records. While I don’t want this post to be too technical, I need you to understand at least what the “TXT record” is there for.
What does Wikipedia say?
A TXT record is an abbreviation for text record and is a type of resource record in the Domain Name System (DNS) used to provide the ability to associate some arbitrary and unformatted text with a host or other name, such as human readable information about a server, network, data center, and other accounting information.
So basically, the TXT record can be any string containing printable ASCII characters.
Let’s get down to business
Alexa (or someone else) provides a CSV with the “Top 1 Million” sites. A few lines of Bash later, I had a file with the TXT records of the first 10.000 pages in this list. After some grep magic to clean the list, there where only a few “funny” or “interesting” TXT records left in the file.
If you’re interested, you can check the TXT record of any domain with the following command (implied that you got “domain information groper” installed):
dig -t txt +short example.com
Only eleven domains got an interesting TXT record…
thepiratebay.se returns “BITTORRENT DENY ALL”, which is actually part of the “DNS Tracker Preferences” of Bittorrent. nyaa.se, on the other hand, replies “BITTORRENT”.
akamaihd.net, the content-delivery network used by companies like Twitter and Facebook, prints “This is not the nameserver you are looking for.”.
Our beloved github.io still got some note left: “Demonstration of domain control for domain github.io. Please send the validation email to email@example.com”
lenovo.com is using the TXT record to advertise: “Visit www.lenovo.com/think for information about Lenovo products and services” — nifty little idea.
(This is the time to apologize: Sorry, I lied. This post isn’t fun.)
pitchfork.com and zulagames.com gave the TXT record a try: First one set the record to “hi”, last one to “test”.
nowvideo.at (which seems to be, according to Google Transparency Report, an illegal platform back then) gives us the info “domain gesperrt” — which translates to “domain blocked”. Looks like this was done by the Austrian registry.
nix.ru (an online hardware retailer) lists the phone number to their IT deparment: “IT dep. +7(495)9✗4–33✗3” (✗ added by me — then again, this is openly available information…).
warbyparker.com (an American brand of glasses) set their TXT record to “hackit.warbyparker.com”. Sadly, this subdomain isn’t available anymore. We can only imagine what we missed there!
Last but not least we got optimizely.com. They reveal a lot of information (like order numbers of certificates, personal names and email addresses). So much that I won’t bother you with this — but feel free to check for yourself.
Today, the TXT record is mostly used for verification of domains, which is required by Google, Yandex and a few others. Then again, this might be a nice place for some kind of easter egg. For example, I could imagine, that companies looking for people who actually have to work with DNS settings are going to announce that they’re hiring there. Be creative!