CefSharp is basically a small version of Google's Chrome Browser.  Some parts of ProSeries, ProTaxOnline and Lacerte are actually the same web "widget", like login.  For ProSeries and Lacerte we host those web widgets in this CefSharp/Chrome Browser, so that we can talk to the widgets and get responses back (for example getting your user details after you login).

It should be safe as long nobody has tampered with it on your machine. Just cause I'm paranoid, if my anti virus flagged it I'd double check it. Go to it in File Explorer, right click and check the digital signature: