Failed opening required

Hello,

I run antivirus via Cpanel and then my website got down as they found lot of viruses ?? , I check error log in cpanel and found some missing file, any one please help me out as I am non technical person and not a developer. What if I reinstall wordpress o upload fresh files ?

[23-Jan-2015 03:26:32 UTC] PHP Fatal error: require(): Failed opening required ‘/home/pakistan/public_html/wp-includes/post.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/pakistan/public_html/wp-settings.php on line 127
[23-Jan-2015 03:26:36 UTC] PHP Warning: require(/home/pakistan/public_html/wp-includes/post.php): failed to open stream: No such file or directory in /home/pakistan/public_html/wp-settings.php on line 127
[23-Jan-2015 03:26:36 UTC] PHP Fatal error: require(): Failed opening required ‘/home/pakistan/public_html/wp-includes/post.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/pakistan/public_html/wp-settings.php on line 127
[23-Jan-2015 03:26:36 UTC] PHP Warning: require(/home/pakistan/public_html/wp-includes/post.php): failed to open stream: No such file or directory in /home/pakistan/public_html/wp-settings.php on line 127
[23-Jan-2015 03:26:36 UTC] PHP Fatal error: require(): Failed opening required ‘/home/pakistan/public_html/wp-includes/post.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/pakistan/public_html/wp-settings.php on line 127
[23-Jan-2015 03:28:01 UTC] PHP Warning: require(/home/pakistan/public_html/wp-includes/post.php): failed to open stream: No such file or directory in /home/pakistan/public_html/wp-settings.php on line 127