Can the error be caused by a virus and how to get rid of it?

Question

CMS

Good afternoon!
A very unpleasant problem arose, during the development of a site on the WordPress CMS, an error popped up very unexpectedly, after which work on the site became impossible. The domain is hosted by Reg.ru. In the development of the site, various plugins are used, such as Elementor, Woocommerce and about 5-8 more add-ons. plugins.
A few days ago, Reg.ru reported that I noticed a virus on the site, after which I bought a subscription to their antivirus and cured the site.
The essence of the error:
1. The site started to be created about a week ago, all the necessary plugins were installed.
2. The day before yesterday I returned to the site and began to finish it.
3. An error occurred between 12 am and 4 pm yesterday. It is important that at this time no actions were taken on the site on my part.



4. After that, I urgently bought a new domain, uploaded it to the same hosting, and started developing the same site completely from scratch on the new domain.
5. I also rolled back the site on the old domain using a backup.
6. Today, in the interval from 14:00 to 14:30 (approximately at 14:10), the same thing happened again on both sites. At the same time, the same mistakes. At the same time, for about 5 minutes they changed from one to another. Errors were generated in completely different php files of the site.

Actually the essence of the question - what could it be? Virus? My curvature? If a virus, then how to get rid of it? If my curvature, then such errors can be a consequence of what?
Also on the same hosting, where the 2 domains that I described above lie, there is also a 3rd domain with a site and everything is fine on it.

Answer 1

Antiviruses do not cure sites, they either delete files altogether, or delete sections of code without understanding where the virus is, and where the native code is already (as they do according to their own pattern), in order to get rid of the virus - you need to find a hole, close it, install a clean WP core and after that, clean up the template / plugins according to the reports of antirus or any free plugins for WP.
Do not use warez, backdoors / worms are embedded in hacked plugins and templates (in 99% of cases), you will never get rid of viruses there.