
Reading through, the problem reported by Avanan is worse than described (Watch the demo video on their site). Basically, hackers take known attacks and make them into zero-day. Microsoft admits it bypasses ALL their security layers, including the premium services - Advanced Threat Protection, Safelinks, etc...
When we moved our company's email to O365, I remember my surprise when the Microsoft salesperson claimed they have the best security. I guess we really wanted to believe it. Afte 2y of non-stop phishing attacks and compromised accounts, I'm back to where I started - I don't trust Microsoft with Security.