a) Many predatory journals are claiming they are indexed by SCOPUS & WOS/JCR with impact factors. You can check the truth by searching these resources:
i) Web of Science (WOS by Clarivate Analytics)
ii) SCOPUS (by Elsevier)
iii) MyJurnal
iv) MyCite
b) Check out Open Access Journal Quality Indicators
c) Retraction Watch – A blog that reports on retractions of scientific papers
d) Tips and tools to spot predatory journal publishers