Does Google Safe Browsing mark WHOLE WEBSITES or INDIVIDUAL PAGES as phishing? If I create 1 phishing page, will all pages of my site be penalized?
Whole website will be marked for phishing. You can go through their FAQ here to understand what they mean by website Link to FAQ
EDIT : "In this data, a “website” refers to the hostname or fully qualified domain name of a URL (e.g.,
somehost.example.com). When we scan a site and identify malicious hosts, we count each distinct host."