And, I, too, am having the exact same problem. Issue started only a few days ago as I get the same alert ("We've blocked the threat HTML:Url-inf[Susp] from harming your computer.") each time I turn on my computer and open up my Firefox browser (vers. 89.0.2 (64-bit)) which is set to open up with the first tab being my normal Yahoo! email account. The screenshot is pretty much the same as shown above (pacard's entry: Reply #2 on: June 23, 2021, 07:44:37 PM).