The polyfill.js is a popular open source library to support older browsers. 100K+ sites embed it using the cdn.polyfill.io domain. Notable users are JSTOR, Intuit and World Economic Forum. However, in February this year, a Chinese company bought the domain and the Github account. Since then, this domain was caught injecting malware on mobile devices via any site that embeds cdn.polyfill.io. Any complaints were quickly removed (archive here) from the Github repository.
ECMAscript is based on JavaScript
I’m not gonna bother entertaining the rest of your post, you can’t seem to even get the basics right
Ecmascript was made to standardize JavaScript, but it isn’t based on JavaScript. Actionscript is then based on ecmascript, making Actionscript a sibling to JavaScript, not a subset.