How to embed a block with your content into the page of a third-party site opened in the user's browser?

Question

JavaScript

It is necessary to embed a small block with content from your site into the page of a third-party site opened in the Yandex browser of a specific user. There is full access to the PC of the specified user. Windows 7 PC. How can this be done?

Answer 1

With a browser extension .
Obviously, you will have to create this yourself, but nothing particularly complicated. Knowledge of JS is enough.
Documentation

Answer 2

redirect the site's ip address to your phishing site in the hosts file. well, or as a proxy and correct the transmitted data.