My parents are running Xubuntu, I think 16.04. Mum was using Firefox, probably facebook, and now has some message on screen saying to call Microsoft immediately, and a voice came from the speakers saying "threat detected". She's rebooted (hard reboot as nothing else worked) but it came back, which is surprising as I though it was just something causing firefox to go full screen. Anyone got experience of this? I'm planning to talk her through switching to another terminal and doing a dist upgrade (already due!), which will hopefully save me going round there (long trip).