I've just noticed a warning for WD MyBook Live NAS users, warning of a malicious net-based attack. Apparently, it uses some sort of remote reset command to reset to factory default condition. i.e. destroys all data.
Unlike the QNAP QLocker ransomware thing, this is just malicious. No warning, no extortion, no demands, just reset.
It seems to apply only to the older "NAS" versions of the MyBook, i.e. with ethernet ports (which I don't have) rather than the current USB (or Firewire, Thunderbolt) etc versions (which I do have but which isn't net-connected).
WD seem to have reacted very fast (less than 24 hours, and unlike QNAP) with simple advice .... disconnect any MyBook Live Solo or Duo devices from the internet immediately.