Software experts from Trail of Bits have sandboxed Windows Defender, the default antivirus solution that ships with recent Windows editions. Sandboxing is a technical term that describes the act of running an application inside a dedicated container. Microsoft acquired GIANT AntiSpyware in 2004, and it used it as the starting point for the Defender app. Researchers open-sourced a framework called AppJailLauncher that runs Windows applications inside their own AppContainers. The team also released a sandboxed version of Windows Defender on GitHub as well.
Source: https://www.bleepingcomputer.com/news/security/researchers-put-windows-defender-in-a-sandbox-to-show-microsoft-how-its-done/