Where does OS X get defaults from in Guest User Web access Parental Controls? I did not put these here, I don't know where they came from. WHOIS by IP seems to indicate they are from Amsterdam? (149.154.175.50 copy-pastable for anyone who wants to check)
Using online tools it appears that as of this date/time that is a hard coded IP address from the app called Telegram or Telegram Messenger.   

Why it's hard coded into the app as IP address doesn't make sense, but it seems to be where it is coming from.