We created the module Virus Scan 4 Mendix you mentioned in your post. The API Ronald mentioned can be used only if the application is used for Non-Commercial use. For that reason we developed another API which provide a paid service and we built a Mendix module for that. Please contact our Bas for the options and plans.
We have implemented this module for 3 financial companies already and they investigated if al the (privacy) rules and laws are ok when using this module.
I wrote a blog about the implementation of this module to get you quickly up and running!
This one should be feasable: https://www.virustotal.com/nl/faq/#virustotal-api
There are more out there but this one is one of the largest I think.