Office 365 will help admins find impersonation attack targets By 12:05 PM Microsoft will make it easier for Defender for Office 365 customers to identify users and domains targeted in impersonation-based phishing attacks as recently revealed on the Microsoft 365 roadmap. Defender for Office 365 (previously known as Office 365 Advanced Threat Protection) protects the emails of Office 365 enterprise accounts from various threats including but not limited to credential phishing and business email compromise. Impersonation happens when a threat actor uses a sender or domain in an email message designed to closely resemble a real sender or domain (michele@contoso.com instead of michelle@contoso.com and ćóntoso.com instead of contoso.com).