Where did spam traffic from Yandex come from?

Question

Search Engine Optimization

Good afternoon, dear experts in the field of SEO, traffic and spam.
On one of the sites about 2 weeks ago, to put it mildly, dubious traffic appeared (on the screen). The site is an industrial theme and is in no way connected with the direction of xxx. Spam traffic has been on the rise for the past 2 weeks, which is causing some concern.
We rechecked all the sources, the database (and even rolled back half a year ago), checked the server for possible vulnerabilities, checked DNS records, no subdomains - we didn’t find anything malicious on the site and in its environment.
A site in the Z, G index is not ranked for spam queries, at least up to a depth of 500 in the respective regions. The site itself is being promoted in the top ten without any black methods, an active campaign for contextual advertising is being conducted - everything is clean there too.
Then where does this come from:

Actually a couple of questions:
1. What else can be done? Is it possible to reject these users (or bots) by creating a referrer rule in htaccess, for example, not to let everyone who comes in response to a sex request enter the site?
2. Is it possible to spam with referrer substitution to "mislead" PS?
3. Obviously, these are the tricks of a competitor, there are even suggestions of who exactly.
I would be very grateful for your valuable advice! I don't know where to dig anymore.

Answer 1

This is spam, most likely bots (but there could be people - if the transitions were according to the words for which you are in the search results - "to worsen the PF"), most likely a competitor. But sooner or later he will run out of money or patience. Because your site will not get anything from such manipulations. So relax and keep working. For greater certainty, you can unsubscribe to Yandex technical support.