> Why was the printer connected to the public internet? A DMZ subnet would have prevented this vector of attack.
Aren't most network printers connected to office networks with public internet access? I sounds like this printer was making outgoing connections, and I doubt many people/companies go through the trouble of specially blocking those from printers.
You'd have to be especially security conscious and paranoid (especially 20 years ago!), to be operating under the assumption that your own equipment is working against you.
Eh, typical "user hostile hardware and software" is not even in the same league as exfiltrating your data to an adversary.
And to be honest, (I have been out of it for a few years now) I have yet to see a company block OUTGOING access on a DMZ.
You see it often in Universities, but also in larger businesses where you want to stop someone from accidentally printing 5000 copies instead of 50, or having print jobs stack up on top of each other in the output tray (think HR/sensitive information being scooped up by accident.)