Weird gibberish characters appearing on bottom of Drupal 7 pages
Since these characters appearing within certain section of the website, you need to identify the source of it and which rendering element is responsible for it (either template file or some function).

The easiest way would be to track it down by enabling theme_debug variable in your settings file which enable you to debug the output of the rendering engine.

So please add this line into your settings file:

$conf['theme_debug'] = TRUE;


then refresh the page and check the source code to see which rendering element is outputting this.



For more advanced solution, use PHP debugger such as phpdbg (in PHP >=5.6 core) or XDebug (which allows you to generate a trace file and find the source of the problem). Here is sample xdebug.ini config, so in your scenario you just need to enable xdebug.auto_trace, generate a trace file for single page load, then disable the setting (since it hugely impacts the overall performance). Then open a generated trace file, look for gibberish where they've started to appear and find out which code is generating it.