1Passwords browser extension has always been designed from the outset to keep you safe from some recently discovered browser based attacks on some password managers. 1Password is designed in such a way as to not be vulnerable to the kinds of attacks those scripts used. The scripts that attempt this are from Adthink (audience insights) and OnAudience (behavioralengine) Researchers at Princeton University were investigating tracking scripts on web pages and discovered that several of them attack browser-based password managers and extract email addresses, usernames and sites stored in the browser.”]
Source: https://blog.1password.com/1password-keeps-you-safe-by-keeping-you-in-the-loop/