Microsoft Cloud App Security (CAS) – https://www.microsoft.com/en-us/cloud-platform/cloud-app-security
Part 1: Credit Card Numbers
In this blog post, I am going to cover how to setup alerts and enforce Data Loss Prevention when a file containing credit card number is detected in a sanctioned cloud app. A sanctioned app is a cloud application that has been approved in the Cloud App Security console.
You can read the entire blog post from here - https://blogs.technet.microsoft.com/scdsec/2016/08/22/microsoft-cloud-app-security-part-1-credit-card-numbers/