This article shows how to find the FTP credentials and connect with a popular free application Filezilla (or the credentials will work for other options as well).
(if you can’t login with the listed Host Name, try using the IP address)
Here is more information on what to do if hacked.
Malicious WordPress Plugins
Can use Google’s Safe Browsing technology to examines the wordpress website URLs looking for unsafe websites that have been compromised. Google detect unsafe sites, and show warnings on Google Search and in web browsers. You can search to see whether a website is currently dangerous to visit. https://transparencyreport.google.com/safe-browsing/search