Go to this page: https://products.office.com/en-us/office-online/view-office-documents-online
If you paste a url of an office document(e.g. http://ieee802.org:80/secmail/docIZSEwEqHFr.doc) to the input box and click "create url", it will generate a url which allows you to view the file in browser.
It expires after 15min so by the time anyone sees this it must have been expired, but I guarantee it is a valid url and if you paste that in browser it will download that doc. This was working about 2 months ago, but not working now, I wonder if Microsoft has changed something, does anyone know the reason?