conhost.exe is a program which is probably legit. So, if conhost.exe is on your computer, it is probably ok, and will NOT be a cause for concern. Even if your PC is virus-free, it is still recommended to use a well-known antivirus with a good track record, in order to yourself your PC against viruses and malware.
Usually, the default filename and path where the program is stored is
C:\WINDOWS\system32\conhost.exe.
The MD5 fingerprint for this file is d752c96401e2540a443c599154fc6fa9.
This program is NOT registered as a Windows service. This is very good.
conhost.exe seems to use the functions of Windows SFC (System File Checker) or Windows File Protection.
This is a x64 executable. It uses the full capacity of modern CPUs.
This task does NOT have visible windows. This is most likely a bad sign.
conhost.exe is digitally signed. Today the large majority of virus-free software applications are digitally signed.
The digital signature extracted from conhost.exe verifies as ok. This is excellent.
Digital certificate name: Microsoft Windows
Certificate's issuer name: Microsoft Windows Production PCA 2011
This application does NOT have a removal routine set up in registry.