In normal conditions there are several ways to check ports on a system.And there are lots of tools around like SysInternals, TCPView or good old “netstat -ano”.
But wait a minute, if we look netstat -ano;
As you can see my port 80 is reserved by “System” process (where PID=4) . Well it is easy to understand if your server installed Web Server like Apache, IIS or IISExpress to figure out who is using it but what if you don’t have any web server in your machine but who is then using port 80 ? OS itself ?
Well, I can tell you, definetly it is not “system” process itself. System process is only serving requested port for another process if your application utilize http.sys driver.
HTTP.SYS is a kernel driver so runs under system process obviously.
Even you can use C# “HttpListener” to create small program that listen on a port by utulizing http.sys easily.
https://docs.microsoft.com/en-us/dotnet/api/system.net.httplistener?view=netframework-4.8
But is there any way to see which process actually using http.sys and bind this port ?
Yes.
“Netsh http show servicestate”
It will give you all bindings for registered sessions.
Registered URLs:
Server session ID: FF00000220000001
http://+:80/116B50EB-ECE2-41AC-8429-9F9E963361B7/
Server session ID: FF00000020000001
http://+:5985/WSMAN/
http://+:47001/WSMAN/
Server session ID: FF00000120000001
http://*:5357/584BBA7C-0F20-4161-BB0E-0D83BD7CA684/
Server session ID: FD0000012000001F
http://*:8855/
if you check the request queues section in results you can also see process identifiers.
Well the command results not exactly user friendly to show which PID matching which binding.But each session id order also match on printed request queue result.
Request queues:
Request queue name: Request queue is unnamed.
Version: 2.0
State: Active
Request queue 503 verbosity level: Basic
Max requests: 1000
Number of active processes attached: 1
Process IDs: /*first one*/
6392
Request queue name: Request queue is unnamed.
Version: 1.0
State: Active
Request queue 503 verbosity level: Basic
Max requests: 1000
Number of active processes attached: 1
Process IDs: /*Second one */
16076
Request queue name: Request queue is unnamed.
Version: 2.0
State: Active
Request queue 503 verbosity level: Basic
Max requests: 1000
Number of active processes attached: 1
Process IDs: /* Third one*/
23588
Request queue name: Request queue is unnamed.
Version: 2.0
State: Active
Request queue 503 verbosity level: Basic
Max requests: 1000
Number of active processes attached: 1
Process IDs: /* Forth one*/
19552
If i am looking for “HTTP://*:8855/” this binding the process ID is 19552.
For my port 80. PID => 6392.
When i checked with taskmanager; it is svchost.exe. Commandline column of task manager says:
PeerDistSvc is the guy in my case.
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