nsupdate and Microsoft DNS Server

[Jonathan de Boyne Pollard]

MF> Nsupdate is a trojan that's associated with those porn site
MF> autodialers. See here:
MF><URL:http://www.liutilities.com/products/wintaskspro/processlibrary/nsupdate/>
MF> [...]

What you're missing is that (<sigh>) he multi-posted this exact same
question to the BIND discussion forum.  He's talking about the
"nsupdate" that comes with BIND.