nosunkcosts

Thanks for your suggestions, @alvarnell. On @treed's advise (DM), I tried disabling each of my extensions one by one and it turned out the culprit was "Adblock for Youtube™". It would throw that message when I visited seemingly random sites (eg. nytimes.com, forums.malwarebytes.com), and started happening only a few days ago. I've reported it on the "Adblock for Youtube™" support service: https://chrome.google.com/webstore/detail/adblock-for-youtube/cmedhionkhpnakcndndgjdbohmhepckk/support?hl=en-US I just hope the extension was trying to generate benign advertising popups.. rather than anything more malicious like steal information.

I'm running the latest Malwarebytes and unfortunately it's not catching this pesky malware that causes Chrome to throw up this error message when I visit certain sites. How can I investigate this further and fix it? Thank you all very much.