The approved tool was fine. The free one was not.
The company approved one AI chat tool with a data agreement. An analyst preferred a free desktop app for questions about spreadsheets. Nothing in the existing stack noticed, because the app looked like any other program and the traffic looked like any other HTTPS.
Endpoint Observation listed the app on the device, matched its use to the finance policy, and showed three quarterly close files leaving toward an external model API during the quiet period before results.
The fix took a day. The report to legal had timestamps instead of estimates.