This popped up suddenly while surfing the net. Mozilla says it’s malware, so did my antivirus software (I use Kaspersky and recommend it.) Firefox does not install patches through sudden and unexpected pop-ups. This is an evil-doer. If you see it on your screen, close your browser immediately. Firefox updates automatically, and doesn’t notify you that it has. It’s probably the right way to do it. DON’T LET THIS INSTALL!
Urgent Firefox Updates Don’t Happen This Way!