title: Unauthenticated user in mysql processes list - hack attempt?
body: <p>I see frequently when I run <code>mysqladmin proc</code> or when I review the MySQL Server process list a user marked with: unauthenticated user trying to connect.</p>
  
  <pre><code>+-----+----------------------+--------------+-----------------+---------+------+------------------+------------------+-----------+---------------+-----------+
  | Id  | User                 | Host         | db              | Command | Time | State            | Info             | Rows_sent | Rows_examined | Rows_read |
  +-----+----------------------+--------------+-----------------+---------+------+------------------+------------------+-----------+---------------+-----------+
  | 40  | unauthenticated user | x.x.x.x:xxxx |                 | Connect |      | Reading from net |                  | 0         | 0             | 0         |
  </code></pre>
  
  <p>What may causes such thing?</p>
  
  <p>Is that normal, or should I investigate my system for any vulnerability or security breach?</p>
  
  <p>Thanks</p>