What is the significance of port 49153?
What's the need for open ports and what are the steps to secure them? An article I was going through had the following information regarding the use of each port - Ports 135 used by svchost.exe, running "RPC Endpoint manager", RpcSs and MSMQ
Ports 445 used by "System" (?)
Ports 2103,2105,2107 being used by MSMQ
Port 49152 used by "wininit.exe - Windows Start-Up application"
Port 49153 used by svchost.exe, running "TCP/IP NetBIOS Helper", "DHCP Client" and "Windows Event Log"
Port 49170 used by services.exe
There is a wealth of knowledge on well known ports like port 49153 available on the internet and the services that run behind them. I would recommend researching the hardening of the IIS / Windows server and go from there. It's good that you've taken a proactive approach to assess your web server, and understand how it functions. It's not uncommon for known good services to initiate communications and open ports dynamically, so even if your research to a high number port comes empty handed it's not necessarily something to worry about. For the most part Windows IIS is pretty secure out of the box and doesn't require too much tweaking, but just ensure that you're updating your server with patches regularly. These days most attackers will focus on the web application running on your server, rather than attacking the server itself.
Using TCPView will also provide you with a look into what services are utilising the ports.