Bulk OA Attachment Exfiltration via doc_helper.aspx (949 Files)
This rule detects potential bulk data exfiltration by monitoring for high volumes of file access events (FileAccessed, FileRead, FileModified) originating from the 'doc_helper.aspx' file-management web shell. It summarizes activity by device and user account, flagging instances where over 100 unique files are touched within a short timeframe, which is indicative of automated collection and exfiltration activities.
Microsoft Sentinel (KQL)
