UDP/137 scans -- new worm?

["David Gillett" <gillettdavid () fhda edu>]

  The number of machines probing every IP in our range
with UDP/137 seems to be up substantially today, to the
point where it's practically DoSsing some of our gateway
equipment.

  These are not routine Windows/NetBIOS activity.  Although
the "Packet was broadcast" flag is set in the NetBIOS header,
they are in fact being sent unicast.  The source port in my
captured samples is always the same for any given source
address.

  The FCS/Checksum is always wrong.  It seems to be random,
which argues for a tool that doesn't care about setting it
rather than that the address/etc has been spoofed.

  Are other people seeing this?  Anyone know what's causing it?

David Gillett



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