Thanks for the provided links. I understand how important it is to timely update software, have trusted antiviruses and THINK. I know many examples of phone scams when thieves wanted to learn credit card data from people pretending to be bank representatives. And they know the psychological...
I'm having the same issue with my external drive. What I do when I get this: move the information to other flash drive and then launch the formatting of the erroneous hard drive. And make sure you make the 'Safe ejection' of the flash drive.