It's this kind of malware that gets me concerned for the pizza techs out there that only know how to run scans, and wouldn't think twice if all of their scans came up clean. Had three customers the other week with this virus, seemed to be dropped by Yakes. Customers opened no payload. One of the machines had the Cryptowall 2.0. One of the machines, I had to kill the processes, and then manually remove the registry keys. Not a single scan detected it.
I will be training my techs to recognize this type of stuff. Mainly by teaching them to understand how Windows works, and what's normal and not normal. The hard part is it uses a legitimate process, dllhost.exe. Who's going to think twice about that? It could fool anyone. Aside from the high CPU usage. Even then, there were times on one of the infected machines, the CPU would go back to normal, and then an hour later, the virus would kick back on again.