16:48
Q3_review.xlsx is attached and sent to a client contact. The message is held pre-delivery; the sender's client shows it as sending.
16:48:03
The workbook is extracted in the sandbox. A third worksheet, hidden and not visible in the sender's view, contains 1,340 rows belonging to a different client.
16:48:04
62 Exact Data Match hits against the enrolled customer table. The recipient is known-external and legitimate — but not entitled to that data.
16:48:05
Outcome: quarantine for authorised review. The sender sees a warning naming the category only. No content is echoed, because a sender who is about to make a mistake is not a reason to show them someone else's data.
16:52
The reviewer opens the case, sees the masked evidence under their own role, confirms it, and returns the message to the sender for correction.
Recorded
One quarantine, one authorised review with the reveal logged, one release-to-sender. Nothing crossed the boundary, so no notification clock started.
What it came to Had it delivered, this was a personal-data disclosure to an unauthorised third party. Malaysia's PDPA 72-hour clock and the client's own contractual notification terms would both have been running from the moment it was discovered — which, realistically, would have been weeks later.