Microsoft runs DCE RPC on this port as its DCOM service. This is similar to the function of UNIX11port. Services using DCOM and RPC register their locations with the endpoint mapper on the computer. When remote customers connect to their computers, they will look for the location where the endpoint mapper finds the service.
2. Port 139
139 NetBIOS file and print sharing attempts to obtain NetBIOS/SMB services through the connection entered through this port. This protocol is used for Windows File and Printer Sharing and SAMBA. Sharing your hard disk on the Internet is probably the most common problem. 139 belongs to TCP protocol.
3. Port 445
Port 445 is a port with mixed reputation. With it, we can easily access all kinds of * * * folders or * * * printers in the local area network, but it is precisely because of it that hackers have an opportunity. They can secretly enjoy your hard disk through this port, and even format your hard disk silently!
4. Port 3389
Is it Windows? Server remote desktop service port, through which you can connect to a remote server by using connection tools such as "Remote Desktop". If you are connected, you can operate the remote computer like a local computer after entering the user name and password of the system administrator, so the remote server will generally modify the value or close this port.
Extended data
Introduction of common ports
TCP 88=Kerberos krb5 service
TCP 102= Mail Transfer Agent
TCP 108=SNA gateway accesses the server.
TCP 1 10= E-mail (Pop3), ProMail.
TCP 1 15= Simple File Transfer Protocol.
TCP 1 18=SQL service, infected person 1.4.2.
TCP 1 19= NNTP, Happy 99.
TCP 12 1 = JammerKiller，Bo jammerkillah
TCP 123= Network Time Protocol (NTP), network controller.
TCP 135= Microsoft DCE RPC endpoint mapper service.
TCP 137= Microsoft Netbios name service (used by network neighbors to transfer files)
TCP 138= Microsoft Netbios name service (used by network neighbors to transfer files)
TCP 139= Microsoft Netbios name service (for files and printers * * *).