I have a similar issue wherein every day, with the Wordfence e-mail update, I receive one issue, a variation on the following…
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/classes/CleanUp.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/classes/Main.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/classes/Update.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/_admin-page-settings-plugin-areas/_common-files-unload.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded-assets/_asset-script-single-row.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded-assets/_asset-style-single-row.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded-assets/view-by-loaded-unloaded.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded-assets/view-by-location.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded-assets/view-by-parents.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded-assets/view-by-position.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded-assets/view-default.php
* Modified plugin file: wp-content/plugins/wp-asset-clean-up/templates/meta-box-loaded.php
I’m wondering… Is this normal or signs that this plugin has been hacked?