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.
Viedoc - EDC, ePRO, eCRF, eTMF, CDMS, electronic data capture, clinical trial and PMS software
Dropbox - Online Sync and File Sharing
Medidata CTMS - Medidata CTMS seamlessly integrates with Medidata Rave to provide real-time views into study progress without manual tracking.
Google Drive - Access and sync your files anywhere
Veeva CRM - Veeva Systems - Cloud-Based Business Solutions for the Global Life Sciences Industry
Mega - Secure File Storage and collaboration