Just a few days ago, Hangouts users saw a number of mysterious "FCM Messages" test notifications, and now Microsoft Teams is exhibiting the same issue. The two incidents are likely linked, as they're connected to a recently published vulnerability in Google's push notification service Firebase Cloud Messaging (hence "FCM Messages"). Ultimately, the messages appear to be harmless (if annoying) for users, so you don't need to worry about the safety of your account or phone.

Read More