Anyone using the Microsoft Teams videoconferencing service and corporate messenger application may have been surprised in recent days with bizarre and successive messages coming from the tool.
The note sent several times only said “FCM Messages” as the title and “Test Notification !!!!!” as content. Users on various social networks and from all over the world, including Brazil, questioned what this would be and if the security of their devices would be compromised.
On the afternoon of last Thursday (27), Microsoft ruled on the case. She confirmed that the bug only affected Android devices and that an update was sent to the app to stop sending notifications.
However, the company guarantees that they are harmless and do not cause any harm to the user, and you just have to ignore and dismiss the messages. “We recommend discarding these notifications without interacting with them,” says the statement.
We're investigating an issue where users are receiving Test notifications on their mobile devices. Further updates will be provided under the SI TM221041 in your admin center.
— Microsoft 365 Status (@MSFT365Status) August 27, 2020
The problem would be in Firebase Cloud Messaging (the FCM, in the original acronym), which is Google’s push notification service that is used in several services. A vulnerability was discovered a few days ago in the tool and Google Hangouts users also received the same message a few days ago.
The companies did not detail the cause of the notifications. It can also be some kind of exploitation of the resource by third parties, or tests carried out by FCM to confirm that everything is operating as it should.