File does not exist: /var/www/html/

Hi,

In error.log, I have a lot of line
File does not exist: /var/www/html/404.shtml
File does not exist: /var/www/html/xxxxx

I test some of the IP that provoque these errors, and all comes from China.

How to stop it ? Is it dangerous ?
If it is not dangerous, how to not have these files in error.log ?

Thanks for help

It is not dangerous ... it is just bots scanning your server for various files or folders. Dont worry about it happens to every server connected to the internet.