Does anyone know what these are?

Had several systems lately, including mine, with incoming connection requests on varying UDP ports, to remote address DEVNULL.megaprovider.nl, which is a past known spammer host. Also now 66.36.251.44, which is an Apache test page on the HopOne ISP.

I haven't found anything on these systems to explain these requests, and I've just blocked all ports to them at the moment.