dllhost.exe com surrogate is not a virus in itself, and if you spot it running in your Windows PC then it is most likely doing an important job that your computer needs it to do.
However, there are security and virus concerns with DLL hosts in general.
A DLL host stands for Dynamically Linked Library, and the best way of explaining it is that it acts like a library of code for other programs to access and run from behind the scenes.
In Windows, this is important because there are often system-vital applications that need to access this code and run quietly in the background.
The danger is if malicious applications gain access to a DLL host then they too can operate without appearing in the TaskManager.
You can still detect malware doing this through a more advanced tool, but it is a significant risk.
The worst part is, Windows has very little reason for still using DLL files.
In short, the presence of a dllhost file is nothing to worry about. But you may want to look into working out exactly what applications are accessing that DLL just to be sure!