Check these two files. Should be what you need.

\ow_smarty\template_c\*************************.file.bottom_menu.html.php 

\ow_system_plugins\base\views\components\bottom_menu.html

Crystal, we strongly recommend not to modify the core files and more over modify the cache files (\ow_smarty\template_c\), because it may lead to the negative consequences. When you update your site or clear the site cache - all the changes you've made will be lost.

If you want to add a simple HTML block to the bottom of all pages - I suggest to develop the plugin or use existing plugins or standard software tools (depends on what exactly you need to add).