Malware bytes group found yet another procedure that targets Mac OS clients running Safari. Malwarebytes group found a recently registered scam site focusing on Mac clients was making the rounds toward the end of last year. The first variation has code that will continue drafting messages (yet does not really send them) and cover the past open windows. The second variant(11.php) will rather open iTunes without any alert in Safari. These defects may have been settled with MacOS Sierra 10.12.2 as Mac clients running a fully up-to-date OS don’t seem to be influenced by the Mail application DoS.”]
Source: https://gbhackers.com/dos-attack-on-mac-os-push-fake-alarms-to-scare-users/