Hello,
among the several security websites and utilities, is there something that may help checking if a connection is subject to a man-in-the-middle attack (e.g. a router hijacking)?

Thank you and Merry Xmas,
/_urka

This site exposes transparent proxies http://www.lagado.com/proxy-test

I know that is just one exploit among many Man In The Middle attacks.

I hope that's a good addition to your bookmarks list.

Your best friend is traceroute..
(except for the fact that you generally can't trace without the target knowing)
It's perfectly possible for "people" with the right resources to insert themselves as MiM on f.ex your VPN-connection.
If your connection gets "laggy" and a traceroute reveals a hop to some "suspicious" IP
and maybe even an increase in "ping" to 200-300ms ( the sat-uplink)
then you can reasonably assume that something fishy is going on.