Security researcher Xusheng Li has released a reverse engineering analysis report, revealing that Microsoft has embedded invisible blind watermarks into AI-generated images within the Paint and Photos/Album applications on Windows. These watermarks employ a GUID (Globally Unique Identifier) assigned by Microsoft's servers as a unique identifier. They function separately from the user-adjustable Microsoft Copilot visible watermark, meaning users cannot fully deactivate them. The process of embedding the watermark includes a prompt review, local NPU (Neural Processing Unit) rendering, and the utilization of the Watermarker.dll component. This ensures that the watermark remains detectable even if the image undergoes cropping, is captured via screenshot, or is partially obscured. In the event that watermark embedding is unsuccessful, the Paint application will halt image generation, whereas the Photos application will record the error but still provide the image to the user.