Noticed github.com wasn't loading correctly on my browser. First I suspected my adblocker, then Firefox, and after it didn't work on Chrome, I knew there was something wrong. Found on reddit [0] that Github and Cyble URLS somehow got added to the URLHaus malware database, which sources lots of malware blockers... and that's why nothing works :).
[0] https://old.reddit.com/r/github/comments/1kx72aa/github_cybl...
Edit - the status page now mentions an issue.