Blank Hash (31d6cfe0d16ae931b73c59d7e0c089c0)

[aluminex]

I am dumping NTDS directly from a 2012 domain controller 


I am seeing the following hash over 50 times 31d6cfe0d16ae931b73c59d7e0c089c0.  The full hash count is a couple thousand, but I wondering why this hash (blank) is showing up and if anyone else has had a similar experience.

[aluminex]

FYI - These accounts do not have a blank password, so I don't why the indicator is blank.