I think GOTOMEETING was for a webinar months ago, I'm not sure why it seems to be latent present on my windows computer.
That is easy to explain.
It was installed and never removed (properly).
Moreover "switch Firewall mode to Public/High Risk: TELE2 ISP network" message in Firewall Log "rules"...
So, your ISP is Tele2 and the firewall has detected that at some point.
Since it is a software firewall, it doesn't matter if modem is on or off.
However in these cases Google Chrome always said "no internet connection"
It would strange/suspicious if Chrome said there was a connection when the modem is off.
If that happens you should start to worry.
It can be that my computer is on another WIFI network in my neighborhood
No, it can't or Chrome would notice it and use it.
Maybe the GOTOMEETING shit on my computer, makes this stealth connection, however coincidentally this is also the same TELE2 ISP as my genuine internet connection, but this makes it not more unrealistic.
No, G2M doesn't make a stealth connection.
It uses your existing connection.
WHY DOES MY AVAST PRO NOT PROTECT OR WARN ME FOR THIS "GOTOMEETING HACK"?
There is no reason for avast to warn because it is no hack.
It is fully legitimate software that you (or someone there) installed for the webinar.
http://www.gotomeeting.nl/