There exists an online list of 'Potential, possible, or probable predatory scholarly open-access publishers' by Jeffrey Beall at http://scholarlyoa.com/publishers/.
The original Beall's list web site (scholarly-oa.com) does not host the list anymore anyway.
I have recenly found a web site https://predatoryjournals.com/ which seems to build on it and expand this list (see https://predatoryjournals.com/about/ )