Fichier FTP infectés/suspects

Mon site internet [URL visible pour les membres Pro] connait quelques bugs, piratages, depuis quelques mois. On a corrigé le problème dans le back office de wordpress pour les permaliens, mais ça n'a rien changé.
Le problème qui persiste viendrait plutôt des fichiers ftp, voici un liste exhaustive qui serait la cause du problème, j'en ai supprimé une dizaine, mais ça ne change rien :

www/wp-admin/edit-tag-form.php"
"www/wp-settings.php"
"www/wp-includes/capabilities.php"
"www/wp-links-opml.php"
"www/wp-admin/edit-form-comment.php"
"www/wp-includes/media-template.php"
"www/wp-includes/class-wp-customize-setting.php"
"www/wp-admin/menu.php"
"www/wp-includes/class.wp-styles.php"
"www/wp-admin/ms-edit.php"
"www/wp-admin/widgets.php"
"www/wp-includes/ms-default-filters.php"
"www/wp-admin/ms-admin.php"
"www/wp-includes/ms-load.php"
"www/wp-includes/load.php"
"www/wp-admin/plugin-editor.php"
"www/wp-includes/nav-menu.php"
"www/wp-admin/link-parse-opml.php"
"www/wp-includes/cron.php"
"www/wp-includes/functions.wp-scripts.php"
"www/wp-admin/upgrade.php"
"www/wp-includes/ms-default-constants.php"
"www/wp-includes/formatting.php"
"www/wp-admin/edit-tags.php"
"www/wp-admin/admin-post.php"
"www/wp-includes/bookmark-template.php"
"www/wp-admin/user-new.php"
"www/wp-includes/widgets.php"
"www/wp-includes/class-wp-customize-section.php"
"www/wp-admin/media.php"
"www/wp-admin/link.php"
"www/wp-admin/custom-header.php"
"www/wp-trackback.php"
"www/wp-includes/general-template.php"
"www/wp-includes/post-template.php"
"www/wp-includes/session.php"
"www/wp-admin/customize.php"
"www/wp-includes/class.wp-scripts.php"
"www/wp-admin/options-discussion.php"
"www/wp-activate.php"
"www/wp-includes/link-template.php"
"www/wp-admin/comment.php"
"www/wp-includes/template-loader.php"
"www/wp-admin/options-reading.php"
"www/wp-includes/feed-rss.php"
"www/wp-includes/theme.php"
"www/lib.xml.php"
"www/wp-admin/network.php"
"www/wp-admin/press-this.php"
"www/wp-admin/options-head.php"
"www/wp-admin/tools.php"
"www/wp-admin/index.php"
"www/wp-config-sample.php"
"www/wp-admin/link-add.php"
"www/index.php"
"www/wp-admin/plugin-install.php"
"www/wp-includes/class-wp-admin-bar.php"
"www/wp-admin/options-media.php"
"www/wp-admin/ms-users.php"
"www/wp-admin/media-upload.php"
"www/wp-includes/locale.php"
"www/wp-admin/update.php"
"www/wp-admin/themes.php"
"www/wp-includes/plugin.php"
"www/wp-includes/script-loader.php"
"www/wp-includes/category.php"
"www/wp-admin/revision.php"
"www/wp-admin/post-new.php"
"www/wp-admin/load-scripts.php"
"www/wp-admin/admin-header.php"
"www/wp-includes/class-pop3.php"
"www/wp-admin/ms-sites.php"
"www/wp-admin/admin-functions.php"
"www/wp-admin/credits.php"
"www/wp-includes/nav-menu-template.php"
"www/wp-admin/ms-upgrade-network.php"
"www/wp-includes/class-wp-http-ixr-client.php"
"www/wp-includes/class-wp-image-editor-imagick.php"
"www/wp-includes/deprecated.php"
"www/wp-admin/media-new.php"
"www/wp-includes/user.php"
"www/wp-admin/edit-comments.php"
"www/wp-includes/default-widgets.php"
"www/wp-includes/category-template.php"
"www/wp-admin/upload.php"
"www/wp-admin/import.php"
"www/wp-admin/async-upload.php"
"www/wp-includes/class-wp-embed.php"
"www/wp-includes/wp-diff.php"
"index.php"
"www/wp-admin/options-writing.php"
"www/wp-admin/edit.php"
"edit-comments.php"
"www/wp-includes/rss-functions.php"
"www/wp-includes/meta.php"
"www/wp-admin/options.php"
"admin.php"
"www/wp-admin/options-general.php"
"www/wp-admin/install-helper.php"
"www/options.php"
"www/wp-includes/class-wp-walker.php"
"www/wp-includes/class-wp-theme.php"
"www/wp-includes/class.wp-dependencies.php"
"www/wp-admin/ms-themes.php"
"www/wp-admin/admin-ajax.php"
"www/wp-includes/feed.php"
"www/wp-comments-post.php"
"www/wp-includes/cache.php"
"www/wp-admin/nav-menus.php"
"www/wp-includes/functions.php"
"www/wp-includes/rewrite.php"
"www/wp-includes/class-oembed.php"
"www/wp-includes/ms-files.php"
"www/wp-admin/edit-link-form.php"
"www/wp-includes/class-wp-customize-widgets.php"
"www/wp-config.php"
"www/wp-includes/default-constants.php"
"www/wp-signup.php"
"www/wp-admin/plugins.php"
"www/wp-admin/install.php"
"www/wp-admin/moderation.php"
"www/wp-includes/canonical.php"
"www/wp-admin/post.php"
"www/wp-includes/shortcodes.php"
"www/wp-includes/revision.php"
"www/wp-admin/theme-editor.php"
"www/wp-includes/post-formats.php"
"www/wp-includes/class-IXR.php"
"www/wp-includes/author-template.php"
"www/wp-admin/admin.php"
"www/wp-admin/menu-header.php"
"www/wp-admin/upgrade-functions.php"
"www/wp-includes/registration.php"
"www/wp-includes/pluggable.php"
"www/wp-includes/ms-functions.php"
"www/column-shortcodes/column-shortcodes.php"
"www/wp-includes/date.php"
"www/wp-includes/option.php"
"www/wp-cron.php"
"www/wp-admin/options-permalink.php"
"www/wp-admin/export.php"
"www/wp-admin/ms-delete-site.php"
"www/wp-admin/freedoms.php"
"www/wp-includes/default-filters.php"
"www/wp-includes/template.php"
"www/wp-admin/ms-options.php"
"www/wp-mail.php"
"www/wp-includes/ms-settings.php"
"www/wp-includes/vars.php"
"www/wp-includes/class-wp-error.php"
"www/wp-includes/bookmark.php"
"www/wp-admin/theme-install.php"
"www/wp-includes/ms-blogs.php"
"www/wp-includes/class-wp-xmlrpc-server.php"
"www/wp-admin/custom-background.php"
"www/wp-includes/class-smtp.php"
"www/wp-includes/class-wp-customize-panel.php"
"www/wp-includes/admin-bar.php"
"www/wp-blog-header.php"
"www/wp-includes/class-wp-image-editor-gd.php"
"www/wp-includes/SimplePie/Credit.php"
"www/wp-includes/SimplePie/Copyright.php"
"www/wp-admin/users.php"
"www/wp-admin/link-manager.php"
"www/wp-includes/comment-template.php"
"www/wp-admin/edit-form-advanced.php"
"www/wp-includes/post-thumbnail-template.php"
"www/wp-includes/query.php"
"www/wp-content/index.php"
"www/wp-includes/ms-deprecated.php"
"www/wp-includes/functions.wp-styles.php"
"www/wp-includes/l10n.php"
"www/wp-admin/load-styles.php"
"www/wp-admin/update-core.php"
"www/wp-includes/class-json.php"
"www/wp-admin/admin-footer.php"
"www/wp-includes/class-feed.php"
"www/wp-admin/my-sites.php"
"www/wp-includes/update.php"
"www/wp-includes/class-wp-editor.php"
"www/web/wp-config.php"
"www/wp-login.php"
"www/wp-includes/comment.php"
"www/wp-includes/class-phpass.php"
"www/wp-load.php"
"www/wp-includes/feed-atom-comments.php"
"www/wp-includes/class-wp-customize-manager.php"
"www/xmlrpc.php"
"www/wp-admin/profile.php"
"www/wp-includes/registration-functions.php"
"www/wp-includes/class-wp-image-editor.php"
"www/wp-includes/class-wp-ajax-response.php"
"www/wp-includes/pluggable-deprecated.php"
"www/wp-includes/media.php"
"www/wp-includes/class-http.php"
"www/wp-includes/wp-db.php"
"www/wp-admin/setup-config.php"

Mais j'ai supprimé une dizaine, ça n'a rien changé. Sur OVH tout parait normal, la page d’accueil s'affiche normalement. Tout est OK. Les sites pornographiques qui s'affichaient sur les iphones ont disparu. Car ce problème venait des htacess. OVH m'a dit de mettre la configuration sur STABLE, mais je suis perdu.
Vous avez une idée.
PS : J'aurai besoin d'un avis, donc évitez de me demander un devis,... Le site me sert de vitrine.
Merci.