The Security Operations Center (SOC) noticed logins to Azure Active Directory (AAD) from yahoo.com and gmail.com email addresses and asked the IT Security team to investigate. At the time, we did not allow many B2B Guest credentials for those domains, but alarmingly, the accounts in question successfully authenticated even though they did not exist in our AAD tenant. Who were those people? Did we have a security breach? What did they access?
A sensitive, internal meeting was held within Microsoft Teams, and someone had accidentally recorded it. The organizer was extremely unhappy when nobody admitted to it, particularly since any attendee was able to download a copy of the recording. An urgent request to the Office 365 and Information Security teams was put out to investigate. How did we go about in doing so?