cefsharp is used by a bunch of wellknown brands, and is generally harmless. It is true that malware may disguise itself as cefsharp, but malware can disguise itself as pretty much any file on your computer.
Here is a quick list of software that uses cefsharp that I just pulled from the web - i think the brandnames on this list should illustrate that this isnt something to worry a lot about.
The process known as CefSharp.BrowserSubprocess belongs to software CefSharp or AOL Desktop Gold or Razer Cortex or Razer Synapse or Alt1 Toolkit or Facebook Games Arcade or Garmin Express or Amazon Cloud Drive or Facebook Gameroom or TigerText Desktop Messenger or Play withSIX Windows client or Amazon Chime by The CefSharp Authors or AOL (
www.aol.com).
It is also used by github and Chromium (i.e. google chrome).