As per https://feedback.azure.com/forums/217298-storage/suggestions/32603164-virus-scanning-for-blob-storage link, Virus scan is not supported for Azure Blob.
Could you please confirm if Virus scan is supported for Azure File Share?
If not, what are the workarounds to scan documents copied to Azure file share?
I don't think Azure File Storage supports virus scan. (Why would it? It's a file storage service, not an antivirus service.)
However, your best option is to use some sort of virus scanner service.
You have not mentioned which technology (.NET, Python, PHP) your app is being built with. If it is .NET, look at this discussion here:
I tried to find online services that have an API for virus scanning. Just found one:
https://developers.virustotal.com/v2.0/reference
If you are looking for an SDK look at this: