When I read this thread and other related threads, it must be Bitdefender causing this problem. I can confirm to see the same warning for both WordPress 4.4 and 4.3.1 websites and started around the same time El Asador Aleman reported.
This webpage https://www.[domain].nl/wp-admin/load-scripts.php?c=1&load%5B%5D=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable,jquery-ui-draggable,jquery-u&load%5B%5D=i-droppable,wp-ajax-response,jquery-color,wp-lists,postbox,nav-menu,plupload&ver=4.4 is identified as infected with malware. Virusname: Trojan.Script.644049
When putting my domain into the white list in Bitdefender I obviously don’t get that message, but then I get the message “Blocked infected file load-scripts.js” in my \appdata\ temp folder
