raise an alert, and a small snippet to make a request to that endpoint: if (document.domain != "login.brand.com") { var l = location.href; var r = document.referrer; var m = new Image(); m.src = "https://brand.com/your-alerting-endpoint?l="+ encodeURI(l) + "&r=" + encodeURI(r); } https://docs.canarytokens.org/guide/cloned-web-token.html
might use Subresource Integrity for its CSS: <link href="/assets/css/stylesheet.min.css" integrity="sha256- +vw3Nb9LyQVDfQI46GQGsC4LuwraLFAN7UNGyt0Nzag=" as="style">