in src/modules/components/viewer.js [258:269]
function addBlankToLinks() {
var iframe = document.getElementById('viewer');
var iframeDoc = iframe.contentDocument;
var ancs = iframeDoc.querySelectorAll('.js-article__body a, .article-body-viewer-selector a');
for (var i = 0; i < ancs.length; i++) {
// If href doesn't contain gutools or theguardian (i.e: links to guardian pages) add blank
if (!/gutools|theguardian/.test(ancs[i].origin)) {
ancs[i].setAttribute('target', '_blank');
ancs[i].setAttribute('rel', 'noopener noreferrer');
}
}
}