basic questions

slistener Port 9000/tcp

A Software Port (usually just called a 'port') is a virtual data connection that can be used by programs to exchange data directly, instead of going through a file or other temporary storage location. The most common of these are TCP and UDP ports which are used to exchange data between computers on the Internet. Port 9000/tcp uses the cslistener protocol for service type cslistener. A malformed request to port 9000/tcp is known to cause denial of service attacks.

Running any firewall software? This is a process intended to monitor port 9000.