Serial Microsoft zero-day leaker NightmareEclipse has found another way to mess with Windows Defender, this time by stopping the antivirus from updating itself. The security researcher, also known as Abdelhamid Naceri, released a proof-of-concept dubbed “BigDiskBuster” that is designed to prevent Microsoft Defender Antivirus from installing platform and security intelligence updates. “Made a funny tool, completely denies defender from updating so you're stuck with your current version if the tool is running in the background,” NightmareEclipse said. The researcher describes BigDiskBuster as similar to their earlier “UnDefend” tool and claims it works on all supported versions of Windows, although they admit the current PoC is “a bit buggy and needs some rewritting [sic].” That…