Apparently there are a handful of reports with Youtube using UDP over this port as well.
David Favor
I probably should have mentioned, on Linux machines, I setup iptables log + drop rules for UDP 443 packets, because I know they're hacks... in my runtime environment.
Then, if these packets every show up in /var/log/kern.log I know it's time to nuke the machine... do an obliteration reinstall from scratch.