Hugh Pickens writes:
Alina Simone writes in the NYT that her mother received a ransom note on the Tuesday before Thanksgiving.“Your files are encrypted,” it announced. “To get the key to decrypt files you have to pay 500 USD.” If she failed to pay within a week, the price would go up to $1,000. After that, her decryption key would be destroyed and any chance of accessing the 5,726 files on her PC — all of her data would be lost forever. "By the time my mom called to ask for my help, it was already Day 6 and the clock was ticking," writes Simone. "My father had already spent all week trying to convince her that losing six months of files wasn’t the end of the world (she had last backed up her computer in May). It was pointless to argue with her. She had thought through all of her options; she wanted to pay." Simone found that it appears to be technologically impossible for anyone to decrypt your files once CryptoWall 2.0 has locked them and so she eventually helped her mother through the process of making a cash deposit to the Bitcoin “wallet” provided by her ransomers and she was able to decrypt her files. “From what we can tell, they almost always honor what they say because they want word to get around that they’re trustworthy criminals who’ll give you your files back," says Chester Wisniewski.
The peddlers of ransomware are clearly businesspeople who have skillfully tested the market with prices as low as $100 and as high as $800,000, which the city of Detroit refused to pay. They are appropriating all the tools of e-commerce and their operations are part of “a very mature, well-oiled capitalist machine" says Wisniewski. “I think they like the idea they don’t have to pretend they’re not criminals. By using the fact that they’re criminals to scare you, it’s just a lot easier on them.”
it's called Copy-on-write (COW) and has been standard in industry for decades but is possible to install at home (using Linux or Solaris).
I am using ZFS on linux, and so far (fingers crossed!!) it has been very stable. The native FS BTRFS for linux is almost ready for use (IMHO).
The point is you don't need to run Linux as your desktop, simply put all your important files on another machines, and using a network filesystem.
Hence, if the cryptoware runs amok on your desktop, you have at least one layer of indirection to prevent the loss of data.
Of course, if you are able to setup a system like this, you probably are more cautious...