What is Cyberduck?
"Cyberduck is a powerful and free software for transferring files over the Internet. It is a very popular FTP client and is used by webmasters from all over the world. You can download the software from here." (Source)

"Cyberduck is a libre server and cloud storage browser for Mac and Windows with support for FTP, SFTP, WebDAV, Amazon S3, OpenStack Swift, Backblaze B2, Microsoft Azure & OneDrive, Google Drive and Dropbox." (Source)

Is cyberduck safe?
"As there are many organizations and individuals within the UNH community that must be able to transfer files as part of daily operations, ISS identified and assessed the following solutions and determined they are safe to use: CyberDuck (Windows, OS X ) " (Source)

How do I install Cyberduck?
"Just download and run the executable installer!" (Source)