Yes, but there is a limitation. The PDF will get protected and converted into both secured formats: (1) protected PDF file and (2) secure web link.  However, the file attachments do not get protected and the user will be able to access them from within Adobe Reader when the protected PDF file is sent to the user. The web viewer does not show the file attachments at all. 

If the PDF attachments are an integral part of the PDF and you need them protected as well, we recommend doing one of two things:

1. Combine them into the PDF so it becomes 1 PDF with no attachments, and then upload them into Vitrium for protection.
2. Add the files separately into Vitrium for protection and send all protected PDF files (or web viewer links) separately to your users.