Changes in core file

Hi,
When scan my site this morning, I got an alert the plugin core.php file ahs been modified. The scan system compared the php in wordpress system and what is in ww.wp.xz.cn system. For example :

add_action(‘blc_cron_check_news’, array($this, ‘check_news’));

was added as line 84 and line 3791 to 3817 are all new lines.

Please confirm if these valid modification by you or issue.

Mansa