k3ym𖺀1d ago

In today's episode of "Can It Run Doom": DNS fucking TXT records.

Some absolute madlad (cough Adam Rice cough) compressed the entire shareware DOOM WAD, split it into around 1,964 chunks, shoved them into Cloudflare TXT records, and wrote a PowerShell script that reassembles and runs the whole goddamn game from DNS queries alone. Nothing touches disk. The DLLs are in DNS. THE FUCKING DLLS ARE IN DNS.

RFC 1035 was written in 1987. Those engineers are spinning in their graves fast enough to generate municipal power.

Bonus: this is a fully functional globally-distributed covert data exfil channel that your NGFW will never fucking see if you're not doing deep DNS inspection. Sleep well.

blog: https://blog.rice.is/post/doom-over-dns/

repo: https://github.com/resumex/doom-over-dns

Also lmao @ every blue team that has never once looked at their DNS query volume. How's that DLP policy working out for you.

It was always DNS.

#infosec #dns #doom #itisalwaysdns

Show threadKarl Auerbach

@k3ym0 I used to have the entire text of the Magna Carta in TXT records in a subdomain.

Even during the early 1990's on the Interop show networks we discovered people streaming lewd stuff via DNS-looking UDP packets.

(Another channel that we used, but it only works on a LAN, is to use the space between the end of a short IP packet and the end of the enclosing Ethernet frame. [Short IP packets are smaller than the minimum size of Ethernet frames.] This was largely used for license key exchanges.)

4:35pmWeb