First of all disconnect your backup drive in an attempt to isolate the problem and hopefully prevent your backups from being corrupted as well.
You will need to search the web for any fix as I don't know of one for this particular one. In any case if you have good backups of your data then a complete reinstall after reformat is probably the cheapest option.
This is a good reason that I keep a backup on a separate USB attached Hard Drive which is always switched off unless I am actually backing up the files to it. Another good suggestion is to install CryptoPrevent in the future. Worth every cent to prevent your situation.