Hey as EPMAP on port 135 is a service which is used to keep a 'map' of what DCE (distributed computing environment) / RPC (remote procedure call - the only DCE technique I know of) services are available on the host and where they are located. When a client wants to contact a given process it asks EPMAP where to find it.


DCE ENDPOINT RESOLUTION

Port 135 is registered as "epmap - DCE endpoint resolution" and can be enumerated by connecting on port 135 and doing the appropriate queries.

Mostly used by Microsoft for RPC locator service, it can be used to lookup what ports other services are running on Distributed Computing Environment (DCE) services on the remote host.

An attacker may use this fact to gain more knowledge about the remote host. Trojans are a common example that exploits this vulnerability.

DCE ENDPOINT RESOLUTION 135 TCP

Services or applications using this port: DCE endpoint resolution The Internet Assigned Numbers Authority ("IANA") has the below description on file for port 135