CryptoWall 4.0 has been released that displays a redesigned ransom note, new filenames, and now encrypts a file’s name along with its data. The most significant change is that it now also encrypts the filename of the encrypted files. For those who may have become infected by this variant, you can visit the dedicated CryptoWall.0: Help_Your_Files Ransomware Support Topic to discuss the infection or receive support on it. Like its predecessors, when installed CryptoWall.0 will inject itself into Explorer.exe and disable System Restore.
Source: https://www.bleepingcomputer.com/news/security/cryptowall-4-0-released-with-new-features-such-as-encrypted-file-names/