FTP session where an empty control-channel command is observed in conjunction with non-printable binary data on the control channel. This pattern reflects malformed or non-FTP-compliant input, commonly seen during TLS handshake attempts on plaintext endpoints, protocol confusion, or automated scanner misfires.

Identifies HTTP requests targeting the web server root path ("/"), typically used for initial service discovery, host validation, or baseline content inspection prior to deeper enumeration.

FTP session where the client issues AUTH TLS to upgrade the connection to TLS and then terminates the session with QUIT without performing further commands. This reflects minimal interaction limited to encryption negotiation and immediate disconnect, commonly observed in capability testing or automated probing.

Identifies HTTPS requests targeting the web server root path ("/"), typically used for initial service discovery, host validation, or baseline content inspection prior to deeper enumeration