FTP_AnoScan is a FTP scanner that can scan a range of IPs looking for servers that allow anonymous logins. Written for Linux.
You can download it from the following link: https://packetstormsecurity.com/files/download/64633/FTP_AnoScan.tar.gz
Source: https://packetstormsecurity.com/files/64633/FTP_AnoScan.tar.gz.html