Cyberduck is a free and open-source FTP, SFTP, WebDAV, S3, Azure Blob, Backblaze B2, and Dropbox client. While primarily known for its macOS version,

there is no official Cyberduck for Windows.

Any software claiming to be Cyberduck for Windows is likely not legitimate and could be malware. There are many alternative FTP clients available for Windows that offer similar functionality.