I missed this few weeks old article: "header includes an [X-Adblock-Key] key that allows daily ads to bypass one of the most popular ad blockers" https://threatpost.com/malvertising-ad-blockers-mac-malware/146861/ … Curious that they are not naming the affected blocker: Adblock Plus (see https://help.eyeo.com/en/adblockplus/how-to-write-filters#sitekey_server …)
Switched to uBlock+uMatrix from AdBlock+NoScript looooooong time ago. The best decision in my life