I still didn't get it. Could you please show me exactly how to override ListBox's default behavior. Everytime when ListBoxItem is selected the Border's background should be changed. Not the background of the whole row but only background of the border which's specified.

 <ListBox ItemsSource="{Binding Source={StaticResource AssetsViewSource}}">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <Border BorderThickness="2" BorderBrush="Black">
                    <StackPanel>
                        <TextBlock Text="Name: " />
                        <TextBlock Text="{Binding Name}" />
                    </StackPanel>
                </Border>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>