In Cloud App Security, under Investigate>Users and Accounts, we are seeing a number of Internal accounts listed that have a 19 digit number as the username, but do not seem to actually exist. eg. 1234567890123456789@<ourdomain>.com. We have others as well that look like they might be a license key/object ID of some kind, formatted as hexadecimal strings without the domain name appended grouped into 8digits-4digits-4digits-4digits-12digits.
Can someone tell me what these are and why they would need investigation?