Monitor for anomalous email activity originating from Windows-hosted applications (e.g., Outlook) where the sending account name or display name does not match the underlying SMTP address. Detect abnormal volume of outbound messages containing sensitive keywords (e.g., 'payment', 'wire transfer') or anomalous login locations for accounts associated with email sending activity.
Monitor mail server logs (Postfix, Sendmail, Exim) for anomalous From headers mismatching authenticated SMTP identities. Detect abnormal relay attempts, spoofed envelope-from values, or large-scale outbound campaigns targeting internal users.
Monitor Mail.app activity or unified logs for anomalous SMTP usage, including mismatches between display name and authenticated AppleID or Exchange credentials. Detect use of third-party mail utilities that attempt to send on behalf of corporate identities.
Monitor SaaS mail platforms (Google Workspace, M365, Okta-integrated apps) for SendAs/SendOnBehalfOf operations where the delegated permissions are unusual or newly granted. Detect impersonation attempts where adversaries configure rules to auto-forward or auto-reply with impersonated content.
Monitor Office Suite applications (Outlook, Word mail merge, Excel macros) for abnormal automated message sending, especially when macros or scripts trigger email delivery. Detect patterns of impersonation language (urgent, payment, executive request) combined with anomalous execution of Office macros.
Stealth (1)