When I save (Ctrl+S) simple HTML file I get a header of 20 KB, full of junk, including some porn. It starts like that
<style type="text/css" id="operaUserStyle"></style><style type="text/css">:root zeus-ad, :root topadblock, :root span[id^="ezoic-pub-ad-placeholder-"], :root guj-ad, :root gpt-ad, :root div[jsdata*="CarouselPLA-"][data-id^="CarouselPLA-"], :root div[id^="zergnet-widget"], :root div[id^="yandex_ad"], :root div[id^="vuukle-ad-"], :root div[id^="sticky_ad_"], :root div[id^="rc-widget-"],
and has such references inside:
a[href^="https://www.mypornstarcams.com/landing/click/"], :root a[href^="https://financeads.net/tc.php?"], :root a[href^="https://www.mrskin.com/tour"], :root a[href^="https://www.kingsoffetish.com/tour?partner_id="], :root
20 KB ... That does not happen when I open files from my disk. I have tested that on different sites and browsers, and other browsers do not add that much junk. I am sure that on my personal computer such sites were never visited. What is going on?