The recent attack against Microsoft’s email infrastructure by a Chinese nation-state actor referred to as Storm-0558 is said to have a broader scope than previously thought. According to cloud security company Wiz, the inactive Microsoft account (MSA) consumer signing key used to forge Azure Active Directory (Azure AD or AAD) tokens to gain illicit access to Outlook Web Access (OWA) and Outlook.com could also have allowed the adversary to forge access tokens for various types of Azure AD applications.

Source: The Hacker News