Unauthorized user in mysql process list - hacking attempt?

Question

I often see when I start mysqladmin proc or when I look at the list of processes in MySQL Server, the user marked: an unauthorized user trying to connect.

 +-----+----------------------+--------------+-----------------+---------+------+------------------+------------------+-----------+---------------+-----------+ | Id | User | Host | db | Command | Time | State | Info | Rows_sent | Rows_examined | Rows_read | +-----+----------------------+--------------+-----------------+---------+------+------------------+------------------+-----------+---------------+-----------+ | 40 | unauthenticated user | xxxx:xxxx | | Connect | | Reading from net | | 0 | 0 | 0 | 

What can cause such a thing?

Is this normal or should I investigate the system for any vulnerability or security breach?

thanks

Answer 1

unauthenticated user is a user who is connected and has not yet sent credentials. This is not like a hack attempt.