wordpress.txt file – Live Feed shows this someone trying to access this non page

Hi

I found in my live feed it says

someone with IP …… tried to access a non-existent page domainname.com.au/security.txt

What is the security.txt file?

Are they trying to hack this site to find this file?

This is not a default wordpress file but is it a hidden file somewhere? Or is this file only found when a site is compromised ?

And this one Activity Detail

arrived from domain2.com.au and tried to access a non-existent page https://domain.com.au/wp-content-uploads/2019/10/logo-2019.jpg

There are quite a few 404 errors that we don’t normally have on this client site.

Please advise.

Thanks