I worked in the networking group for a cloud computing company. You've heard of them. We didn't charge for (some) DNS traffic, so some customers figured out how to use DNS as a transport mechanism to skirt around paying data transfer fees. It would essentially be a DoS attack which affected EVERY customer, so a few could save tiny fractions of their overall spend. A peer team of mine had to deal with the mess. That team had > 100% annual staff turnover, because they just made the oncall staff deal with the problem every time it showed up rather than ever solve the core issue of having a DoS vector masquerading as a feature.
The wild part of DNS is that port 53 is typically open on firewalls and is excellent for data exfiltration/infiltration.
Very cool. I have done similar for playing Bad Apple as well as Doom over DNS:
The cap for record size is 64KB, but you can have an arbitrary number of records, so larger images should be possible by combining multiple TXT record responses into one.
There's also the Iodine project if you want to tunnel raw IPv4 over DNS [53]
You can also create a REST API that accepts domain names and returns IP addresses! Then you can make a webserver that uses the REST API to get the IP address of the image you want to display!
This is cool and all but due to malicious actors abusing this avenue, firewalls as well as endpoint agents will detect and block this. If you create a serious solution that uses this that is, it's great for home use and experimentation I guess.
I wonder is it possible to create a HN clone over DNS?
The image is actually HEIF not AVIF :)
Images over DNS over DNSCrypt over a DNS relay accessed via a VPN acting as a gateway to Tor. Maximum security.
Yes, but why? :)
Oh, this reminds me of a Chrome extension I wrote to distribute Web content (images, html, js, anything) over DNS: https://blog.zorinaq.com/cdn53-a-super-distributed-cdn/ It implements the fake TLD .cdn53: when visiting http://zorinaq.com.cdn53 the extension intercepts the request, sends a DNS query for the TXT record for "_cdn53.zorinaq.com" and the response contains the HTML content, or any content, and it can be up to ~65 kb in size. It's super-distributed as it will naturally be cached by all DNS resolvers worldwide that hit the domain...