Synology forum has several users falling victim to cryptolocker virus for Synology NAS devices
this means that the storage devices will unknowingly encrypt all your data until you pay $350(or not).
When was the last time a ransom note was paid and all was ok again?
Synology Facebook is recommending to power off the DiskStation to avoid more files being encrypted.
Synology support site has not fixed the problem yet.