⚡️ Official word from Microsoft on twitter:
https://twitter.com/MSFT365Status/status/1298898693840609280
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.
Now we have ROUND 2 of such messages, most of us would be getting messages like - "Testing Notifcation from Microsoft to investigate this problem". If yiy watch closely the spelling of Notifation is incorrect. "Notifcation" which definitely makes it more suspicious! This is mostly probably linked to some Firebase exploit.
Many people using Microsoft Teams and Google Hangouts have reported that they have received multiple strange alters in form of push notification on their Android/iOS mobile devices.
The message says
FCM Messages
Test Notification!!!!
FCM Messagess
Test Notificationsss!!!!
FCM Messages
Testing Notifcation from Microsoft to investigate this problem
Clicking on the notification open up the respective App. That's it.
Sequence of events described by users -
- Sudden FCM messages popup on mobile phone.
- Multiple push notifications. 2 reported in many cases.
- Clicking the notification card opens the App.
- App opens normally and does not redirect anywhere, just opens the respective Teams/Hangouts App.
- Message can be ignored and cleared.
There was a recent vulnerability reported for Firebase Cloud Messaging (FCM), allowing to exploit FCM keys stored in APK files in order to broadcast messages to anyone using a Firebase based application. FCM is used by many Apps to deliver push notifications.
These messages seems related and linked to the reported FCM vulnerability.
Though the alert messages seem harmless and can be ignored for now until we get clarification from big giants like Google and Microsoft. Who knows there would be more App being impacted.
More Update:1:55 pm, Thursday, 27 August 2020, Greenwich Mean Time (GMT)⚠️ Some people are now reporting that they are receiving messages "FCM test notificationsss" which seems more suspicious!
There is a Google Hangout support thread that's going on since past two days on the same question: https://support.google.com/hangouts/thread/66799899?hl=en
Microsoft teams reddit page: https://www.reddit.com/r/MicrosoftTeams/comments/ihghrq/test_notification_fcm/
Some users may receive unexpected Test notifications on their Android devices
Microsoft has published this information in Microsoft 365 admin center --> Service Health.The Status shows "Service restored", so we can assume there will be no further such messages.
The message reads
Some users may receive unexpected Test notifications on their Android devices
TM221041, Microsoft Teams, Last updated: August 28, 2020 12:58 AMStart time: August 27, 2020 1:30 PM, End time: August 27, 2020 11:55 PM
Status: Service restored
User impact: Users were receiving unexpected notifications via Teams on their Android mobile devices.
Latest message: Title: Some users may receive unexpected Test notifications on their Android devices
User Impact: Users were receiving unexpected notifications via Teams on their Android mobile devices.
More info: Users may have received notifications that stated: "FCM Messages : Test Notifications" or other similar variations of this message.
Our investigation shows no indication that these messages were malicious in nature; however, we recommend dismissing any of these notifications that were received during the event without interacting with them.
Final status: We've isolated the source of the issue and applied a mitigation. We've confirmed that no further unexpected notifications are being sent to users' Android devices.
Scope of impact: This issue may have potentially impacted any user with Microsoft Teams installed on an Android device.
Start time: Thursday, August 27, 2020, 1:30 PM (8:00 AM UTC)
End time: Thursday, August 27, 2020, 11:55 PM (6:25 PM UTC)
Root cause: A configuration issue within Microsoft Teams systems that facilitate notification delivery was identified and corrected.
Next steps: - We're analyzing the configuration of the systems that manage Microsoft Teams notifications to better understand the underlying source of this issue.
This is the final update for the event.
Some users may receive unexpected Test notifications on their mobile devices
User impact: Users may receive unexpected Test notifications on their mobile devices.
August 27, 2020 10:15 AM CEST
Some users may receive unexpected Test notifications on their mobile devices User Impact: Users may receive unexpected Test notifications on their mobile devices. More info: Users may receive notifications that state: "FCM Messagess : Test Notifications" Current status: We’re investigating an issues were users may receive test notifications on their mobile devices. We'll provide an update within 30 minutes.