viaThe Microsoft 365 Status Twitter account states that the issue only affected Android devices. Thursday afternoon, the account shared that Microsoft had "isolated the source of the issue and applied a mitigation."
People received several random notifications on Microsoft Teams yesterday. The notifications read "FCM Messages Test Notification!!!!" and were sent out repeatedly to people using Microsoft Teams Android.
viaLast week a vulnerability was published for Firebase Cloud Messaging (FCM), which many of Google's apps, including Hangouts, use to deliver notifications. The vulnerability allows someone to exploit FCM keys stored in APK files in order to broadcast messages to anyone using a Firebase-based application — in this case, Hangouts.
Yesterday, some Hangouts users received a suspicious "Test Notification!!!!" alert labeled "FCM Messages." Tapping the message opens the Hangouts conversation list, with no sign of this strange alert anywhere to be seen.
Google Hangouts might not be as popular as it once was, but there are still plenty of people hanging on to it. A good number of Hangouts users across the