Some people just want to watch the world burn. But you're right, it'd be an extremely difficult task on that kind of scale. It's like saying someone could just brick every PC in existing using some magical Windows 0-days.
yeah, they'd need something like a botnet spread out over multiple branches of the internet, to prevent backbone-level shutoffs of the attack, and a metasploit-like framework that could extend the attack vehicle as the number of known vulnerabilities grow leading up to the attack.
... I'm pretty sure the infrastructure exists for organized crime to do this, just going by what I've read in the news.
I would not be surprised if the various cyber-warfare teams for government players have contingency plans in place for doing exactly what you describe. Except they might have more strategic plans in mind than merely bricking the owned devices.
I wonder if there might already be sleeper code in place for this purpose?
Botnet zombies seems to be the most obvious use-case, though. Or create your own TOR-type network to obscure the origin of criminal activity.
With sufficient density of vulnerable devices, you could setup your own mesh network to send your nefarious packets through someone else's Internet gateway miles away.
