HIDE_OVERLAY_WINDOWS is an Android security control that lets an app mark a screen as sensitive so third-party overlay windows cannot be shown on top of it. This matters because overlays are commonly used in GUI deception attacks: malware can place a fake or hidden interface over a real app and capture taps, PINs, or other credentials without the user noticing.
In real banking-fraud campaigns, overlay abuse is used to steal login data, payment details, or one-time PINs from financial apps. By enabling HIDE_OVERLAY_WINDOWS on critical screens such as authentication, payment confirmation, or PIN entry, defenders can reduce the risk of screen-layer interception. It is not a complete solution, but it is an important hardening step alongside permission review, malware detection, and device-risk scoring.