I am working on an ASP.NET application and, as usually, tried to deploy it on IIS Express from Visual Studio. This time, IIS error occured. The error was caused by the application port being occupied by another application (which was pretty strange).
This made me check ports with netstat and what I found was that over 2500 established connections were related to 5KPlayer (which I installed long time ago), and another ~2700 to mDNSResponser. Some of the connections are on the screenshot below:
I immediately killed the 5KPlayer.exe process and connections were also killed. I am wondering if this is something which I should bother about? Could this be some kind of an attack attempt? Is there any way I can check what was happening during these connections?