Get Off Those Maliciously Loaded Scripts!
Download this free Anti-Malware Plugin for WordPress.

I believe that this lb_postrender_handler is a malicious ob_handler that was injected into the code on your site through a eval’d code that is most likely included within a hidden .MO file. The include(‘.hidden_xyz.mo’); is usually inserted into one of your core files, but it could have any name and it could be in any core file. The best way to find it is with the core file definitions included with the automatic update that you get with a premium donation. But I can also help you further if that is not an option for you. You can email me your site details directly if you need more help.

eli AT gotmls DOT net