It went through My Documents and partially or completely encrypted half the files but left the file name. In each folder it affected it left a how_decrypt.gif and howdecrypt.html. I tried cleaning it with Anti-Malware and then attempted a System restore. But upon rebooting Windows said system restore failed because one file could not be restored, but then all System Restore Points and Previous Versions for files were gone .
It seems similar to Cryptowall, but searching for anything called KeyHolder gets no results.