What is a Browser Helper Object (BHO) and how does it work in Internet Explorer?

A BHO is a Microsoft standard that allows third-party developers to interact with Internet Explorer. It runs in the same process and lifecycle as the browser, meaning it starts and ends with the browser page. BHOs can capture and control browser behaviors like navigation events. For more details on BHO implementation, refer to Implementing IE Browser Hijacking Using BHO.