Cure WordPress website of Trojan.Inject.1283 virus

The site is on WordPress, works without failures, there is an iThemes Security plugin and two-factor authentication, the login page is hidden. Antidirus on reg.ru has been swearing at infection for a very long time. The results of the check that comes by mail below. You can see that some of the problems are in the plugin folders that are no longer there (removed from the system) for example mailpoet.

Task: to cure the site without disrupting its performance. You cant roll back because updates appear on the site. Most likely this is manual work, but not very large judging by the report of the antivirus software.

Criteria for evaluating the result:
1. Antivirus scanning of hosting should not reveal problems.
2. All functions of the site must work.

Site address: 4thway.ru

Antivirus message reg.ru:

An antivirus scan showed the presence of malicious code in the following files:

/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/9e/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/wio_backup/2022/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/2022/11/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/70/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/blocks/query-no-results/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/2022/05/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/Requests/Response/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/f9/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/27/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/SimplePie/XML/Declaration/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/blocks/comments-title/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/js/dist/development/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/blocks/pattern/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/blocks/calendar/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-admin/css/colors/light/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/SimplePie/Content/Type/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/blocks/post-author-biography/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/06/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/2020/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-admin/js/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/wc-logs/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/a8/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/blocks/post-date/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/5f/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/sodium_compat/src/Core/Base64/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/4c/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/fc/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/28/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mailpoet/cache/d0/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/js/thickbox/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/wio_backup/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/blocks/site-title/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-admin/css/colors/ocean/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/sodium_compat/src/Core32/Poly1305/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-includes/css/dist/editor/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-admin/includes/.class-wp-cache.php : Trojan.Inject.1283 : -
/var/www/u1696758/data/www/4thway.ru/wp-content/uploads/mai