According to a Microsoft security report, the company is seeing over 13 billion authentications per day for these two services (1.3 billion for AAD), of which, the company says over 10 million (per day) are cyber-attacks.
Microsoft says that there are two systems that help it catch and prevent most of the attackers from taking over accounts, even if they're using valid login credentials.
First off, Microsoft uses an incorrect password lockout system successfully prevents brute-force attacks, and then a location-based blocking feature doesn't allow attackers from accessing accounts from other parts of the world.
Additionally, for Azure Active Directory, administrators can also use the Identity Protection feature to create extra policies that require more authentication from incoming users, or they can decide to block any login attempt outright, based on a risk score assigned to each login operation.
After you install update 3133977 on a Windows 7 x64-based system that includes an ASUS-based main board, the system does not start, and it generates a Secure Boot error on the ASUS BIOS screen. This problem occurs because ASUS allowed the main board to enable the Secure Boot process even though Windows 7 does not support this feature.
Microsoft also has a solution:
The Secure Boot feature is supported in Windows 10. To learn more about the security advantages of this feature and about the upgrade path from Windows 7 to Windows 10, go to the following Windows website: www.microsoft.com/windows
To be fair, this problem is the fault of ASUS rather than Microsoft, but switching the update from optional to recommended is going to be what causes people trouble.