Winsock LSP (Windows Socket Layered Service Provider) is a part of the Service Provider Interface. This interface is very easily one of the very least comprehended aspects of Winsock2. There is a great scarcity of quality information online about Winsock LSP.
A program that is incorporating LSP will use the Windows DLL file and Winsock API to place itself into the communication stack. It will have the ability to read, modify, and intercept network communication. This includes both communication coming to and from the system.
The uses for this type of program within a Microsoft OS are extremely far reaching. Of course, it can cause as much harm as good. As they say, “With much power comes much responsibility.”
Chris