Been getting variations on these only on FlyerTalk for the past few weeks, though they're getting increasing frequency and sometimes intermixed with a Norton Subscription. Also accompanied with an obnoxious 1kHz (ish) tone.

I'm using a Windows 10 Laptop in Virginia, US (using Edge) at the moment, but have also seen variations on Windows 10 desktop (Edge) and Windows 7 (IE 11) in Ohio, US

Screenshot of the most recent one: