udm.net: Research, Ban
a228.sub72.net78.udm.net passed me a porn referrer address. I do not tolerate referrer spam on my site, so I looked them up.
Observation:
a228.sub72.net78.udm.net 78.85.72.228
Pattern:
Fourth, 85, third, then first octet from the host name. It is essentially a reversed ip, except they omit the second octet, the 85.
Research:
sub182.net71.udm.net 62.109.26.122
sub214.net71.udm.net 62.109.27.150
blago.Udm.net 78.85.0.6
Security.udm.net 78.85.0.25