Attack via dllhost.exe?

I have been experiencing what seems like an attack using dllhost.exe.  My machine slows to a crawl and when I open Task Manager, Resource Monitor, I find multiple instances of dllhost.exe running as COM Surrogate.   There are over 20 of these running and they effectively kill the CPU thru over work.  I have tried to kill each one of these individually, but I can't work fast enough as they recreate new instances of themselves as quickly as I delete. 

I've tried running a full system scan and have had several attacks removed or quarantined, but it doesn't seem to cure the problem. 

This seem like it must be a virus or outside attack, but I can't seem to find it.

Can anyone help?

Thanks-