Exchange MailItemsAccessed Harvesting via Known Exfil Toolkit ClientAppId

Ibrahim Saud@tektrix

•updated Sep 21, 2026•0•0•3

Detects Microsoft 365 Exchange MailItemsAccessed operations performed by a specific ClientAppId and AppId known to be associated with an exfiltration toolkit. This activity indicates unauthorized access to mail items, consistent with data harvesting efforts.