The MSSQL module tests accounts against Microsoft MS-SQL service.
It should be noted that MS-SQL Developer Edition and/or MSDE's concurrent workload governor limits you to no more than five concurrent connections to the server at any one time.
The MSSQL module will auto-detect the TCP ports used by the SQL server
instances on the remote host. This is accomplished via a "SQL Ping" UDP
request. If multiple instances are present on the host, only the first
will be tested. Any additional instances will be reported and their
respective TCP port will be noted. The auto-detection can be over-ridden
by specifying a port via the Medusa "-n" option.
Medusa Documentation