As you’ve correctly pointed out, if you’re behind a router, assuming you’ve not placed the PC in the DMZ, or turned the firewall/NAT off, the scan is of the router ports. You need to log on to the router and check the firewall configuration. Also make sure there are no ports unintentionally forwarded.
Really looks as if I will have to live with this one. Don’t like it, not one bit.
Since it appears Quantico is a player in this, it looks as if decisions were made to ensure national security is protected and enabled, albeit with somewhat devious methodology.
Thanks for the links, though. Did learn that modems use linux to run the firmware on them. Changes to this firmware by hacking it may result in degradation of modem performance, so you need to know what you are doing, and even then… no guarantees.