We have made available a feature in Cyberduck 7.6 and later to restore files from Glacier storage class in S3. You can temporarily restore files from Glacier using File → Restore for files with the storage class set to Glacier. The file will be restored using standard retrieval and expire in 2 days after retrieval. Restoring takes some time and attempting to download an item not yet restored will lead to an error The operation is not valid for the object’s storage class.