Is short for Windows Sockets API. It is a standard that specifies how Windows networking software should deal with TCP/IP traffic. One of the features of Winsock 2 is the LSP (Layered Service Provider). A method to insert a file (usually a DLL) into the TCP/IP stack and intercept and modify inbound and outbound Internet traffic. You can read more about LSP hijackers in our blog post, Changes in the LSP stack.