For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Dropbox - Online Sync and File Sharing
DigitalChalk - Online Training Software and Learning Management System (LMS)
Google Drive - Access and sync your files anywhere
Workplace by Facebook - Connect everyone in your company and turn ideas into action.
Mega - Secure File Storage and collaboration
Moxtra - Moxtra is a multi layered, embeddable team collaboration solution.