WHEN MFA WASN'T ENOUGH: A REAL AITM INCIDENT REVIEW

Summary from the TLDR InfoSec newsletter

Attackers have shifted from credential theft to stealing authentication tokens for initial access. In one incident that the author observed, an attacker successfully stole an authentication token via an attacker-in-the-middle (AitM) Microsoft 365 proxy, but couldn't achieve their goals due to rapid detection and response. In a second incident, the attacker was unable to steal a token because the organization utilized FIDO2 security keys, so the authentication attempt through the AitM proxy failed.