Bitrix is ​​spammed by new users. How to be?

Question

1C-Bitrix

Good afternoon.
Recently (approximately since the beginning of 2020), cases of bot registration have become more frequent on some bitrix sites.
Moreover, there are no registration / authorization forms on the site at all. Those. a loophole somewhere inside the Bitrix core.
Yes, the Bitrix is ​​​​not the latest build - the core has not been updated for a year and a half (on all sites with a similar problem)
Can anyone come across? Is it possible to get by with a little bloodshed (fix a couple of files) or is it necessary to update the entire kernel?
UPD: So far I have solved the situation by setting the settings: "Module settings - main module - authorization - Whether to allow users to register on their own." and added a checkbox to enable the registration confirmation process by e-mail (in the same block). I will follow.

Answer 1

Disable registration in the main module settings.
Settings - settings - module settings - main module - authorization tab - there is a checkbox "allow user registration

Answer 2

Not sure, but try this:

#Блокируем ботов через .htaccess
RewriteEngine On
RewriteCond %{QUERY_STRING} register= [NC]
RewriteRule ^.*$ - [R=404,L]