Embed Notice

On a related note, based on the last few times I've been hit with an ad like that, I've been eventually forwarded to a *real* McAfee checkout page, product already in cart, ready to give them money.

I see two possibilities here:
1) Malware site detects a platform that the scammer's not prepared to remote into
2) McAfee has some sort of referral/affiliate program, which makes them complicit in malicious scareware takeover ads.