Riley, a skilled hacker, focused on infiltrating an organization with the intention of compromising Azure AD credentials. Employing a deceptive strategy, Riley made misleading calls to an unsuspecting employee while impersonating a legitimate team member. Concurrently, Riley utilized phishing emails as a method to surreptitiously obtain the Azure AD credentials, thereby posing a significant threat to the security of the targeted employee's account. What specific technique did Riley utilize to compromise the Azure AD credentials?