Just to close this off for anyone else reading this in the future.
This was not a security issue.
The Rogers DNS team has investigated and it appears it's a load-balancer/caching server timing issue for non-existent domains and the fact that my firewall rejects responses from servers it doesn't initiate contact with.
Tables will be broken, ladders climbed, chairs bent, and some careers will never be the same. Don't miss RAW Superstars Roman Reigns, Sasha Banks, Alexa Bliss, Seth Rollins, Finn Balor, Braun Strowman and more!