Site hacked for the third time in 5 days.

I have having a weird situation trying to create a new site.
I installed the db and the core files, set the Akismet key and set the permissions of wp-config.php to 640 , but after some hours the site gets hacked, still in the same way:

the .htaccess and index.php files are modified, making the site unusable.

.htaccess has these lines added in the beginning:

<FilesMatch ".(py|exe|php)$">
 Order allow,deny
 Deny from all
</FilesMatch>
<FilesMatch "^(index.php|lock360.php|wp-l0gin.php|wp-the1me.php|wp-scr1pts.php|wp-admin.php|radio.php|content.php|admin.php|wp-l
ogin.php|about.php)$">
 Order allow,deny
 Allow from all
</FilesMatch>

I’m working on Ubuntu 22.04 server.
I have other sites on the phisical server that still not experienced this problem. Is it a virus? Does anyone have any news?
TIA

• This topic was modified 1 year, 6 months ago by Francesco Garganese.