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.
This is why ublock origin is an essential security tool.
What rules can we add that solve this problem? (I’ve tried DDG but didn’t find any results)
This one is already in the default
uBlock filters - Badware risksI also strongly suggest adding https://big.oisd.nl/ as a filter list. It’s a large and well maintained domain blocklist (sourced from combining lots of other blocklists) that usually adds lots of these sorts of domains quickly and has very few false positives.
If you want to take it even further, check out the Pro list and Thread Intelligence Feeds list here https://github.com/hagezi/dns-blocklists
These can all be added to a pihole too if you use one.
cdn.polyfill.io^ ? By now it was probably already added to the default lista tho…
(I dont really understant these things tho, so correct me if I’m wrong)