I have encountered the files generated by CryptoWall on my computer. But there's only one HELP_YOUR_FILES.png no txt or html. Then there are the "crypted" files for example ey8u4.db9o which looks like the files created by CryptoWall. So I went on a hunt for these files and couldn't find them too often, I have a lot of folders and I could only find them in some folders. Next thing I did i checked when were they created, most of them I cecked were created in 2015's December, it's 2016 October now, so my conclusion would be that there are two possible answers to this one: It's either a fake CryptoWall trying to look like CryptoWall but not having the crypting ability to it creating some random files, or it could be CryptoWall somehow failing to work.