Pages appeared in the webmaster, but are missing from the site?

Question

Search Engine Optimization

Actually, the question is the following.
The site, apparently, was infected with some kind of crap, as links like this appeared in the webmaster:

https://mysite.com/index.php/internet-kazino-igrovie-avtomati-na-dengi
https://mysite.com/vulkan-na-dengi-rubli
https://mysite.com/vulkan-onlajn-na-realnie-dengi
https://mysite.com/index.php/igrovie-avtomati-na-nastoyashie-dengi
https://mysite.com/index.php/igrovie-avtomati-igrat-s-registraciej-na-dengi
https://mysite.com/kazino-vulkan-igrat-onlajn-na-realnie-dengi
https://mysite.com/onlajn-kazino-vulkan-na-realnie-dengi

But I can't find them, the site's file structure is fine.
In robots and sitemap they are not. Not on the site itself either, instead of them 404 (regular, not modified).
Externally, the site has not changed. There was 1 file in the root, rolled back through the git, it disappeared.
Where could the links come from in Yandex.webmaster if they are not on the site?
There are also no links to them, from any place on the site, I scanned the entire project.

Answer 1

forward
not, well, there is a possibility that Yandex is broken

Answer 2

it is obvious that there was a virus that created these links,
you deleted it, and it is obvious that you cannot find traces of the virus that you deleted

Answer 3

On our site we publish links to your "viral" pages. We give our page to Yandex robots - they go to your site. Next is your situation.