In error logs I have this:
[13-Dec-2012 02:42:19] PHP Warning: preg_match() expects parameter 2 to be string, array given in /home/xxxxxxxxx/public_html/site.com/wp-content/plugins/wordfence/lib/wfDB.php on line 146
[13-Dec-2012 02:42:19] PHP Warning: mysql_real_escape_string() expects parameter 1 to be string, array given in /home/xxxxxxx/public_html/site.com/wp-content/plugins/wordfence/lib/wfDB.php on line 149
[12-Dec-2012 17:14:49] WordPress database error MySQL server has gone away for query SELECT ID, post_content, meta_id FROM x_posts, x_postmeta WHERE x_posts.ID = x_postmeta.post_id AND x_postmeta.meta_key = '_pingme' LIMIT 1 made by do_action_ref_array, call_user_func_array, do_all_pings
[12-Dec-2012 17:14:49] WordPress database error MySQL server has gone away for query SELECT ID, post_content, meta_id FROM x_posts, x_postmeta WHERE x_posts.ID = x_postmeta.post_id AND x_postmeta.meta_key = '_encloseme' LIMIT 1 made by do_action_ref_array, call_user_func_array, do_all_pings
[12-Dec-2012 17:14:49] WordPress database error MySQL server has gone away for query SELECT ID FROM x_posts WHERE to_ping <> '' AND post_status = 'publish' made by do_action_ref_array, call_user_func_array, do_all_pings
[12-Dec-2012 17:14:55] WordPress database error MySQL server has gone away for query SELECT option_value FROM x_options WHERE option_name = '_transient_doing_cron' LIMIT 1 made by _get_cron_lock
[12-Dec-2012 20:54:51] PHP Warning: preg_match() expects parameter 2 to be string, array given in /home/xxxxxxx/public_html/site.com/wp-content/plugins/wordfence/lib/wfDB.php on line 146
I deleted this plugin before been hacked.