A possible backup file was found on your web-server. These files are usually created by developers to backup their work.
Remove the file(s) if they are not required on your website. As an additional step, it is recommended to implement a security policy within your organization to disallow creation of backup files in directories accessible from the web.
Testing for Old, Backup and Unreferenced Files (OWASP-CM-006)
Security Tips for Server Configuration