Lapsus$ and SolarWinds hackers both use the same old trick to bypass MFA
Microsoft's MFA is terrible. You install an app called Authenticator. Then when you login the Authenticator app gets a push notification, and the user has to say whether to allow the login or not. If you accidentally press Yes, the attacker gets in. And here's why this is a serious problem: When you use Remote Desktop to work, any time you have a network issue RDP automatically reconnects and you get an Authenticator notification. So during the work day you get frequent prompts that are automatically initiated by RDP reconnects. You get used to automatically saying Yes to the prompt. So when one of these prompts is initiated by an attacker's login there is no way to know, and you automatically answer Yes.