Your sites maybe clean, send a mail about this to avast, so they can check it, when a FP is found, they are known to soon solve it with a next update…
But there are problems at the first site you mentioned,
Wordpress theme: http://www.qweery.nl/wp-content/themes/default/
Wordpress internal path: /home/qweery.nl/www/wp-content/themes/default/index.php (vulnerable)
Wordpress internal path: /home/qweery.nl/www/wp-content/themes/default/index.php (vulnerable)
Wordpress version outdated: Upgrade required.
Bedankt voor het melden en succes met uw online activiteiten,