File Transfer Protocol (FTP) is a standard network protocol used to copy a file from one host to another over a TCP/IP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server applications, which solves the problem of different end host configurations (i.e., Operating System, file names). FTP is used with user-based password authentication or with anonymous user access.

This SonicWALL signature identifies legitimate FTP GET/RETR Command in control channel traffic over any TCP port.