THE researcher known online as Nightmare Eclipse has revealed his identity as Abdelhamid Naceri and released a new Microsoft Defender proof-of-concept exploit called BigDiskBuster. Published on GitHub over the weekend, the tool is described as similar to UnDefend and is intended to prevent Windows Defender from completing platform and signature updates. Naceri says it works on all currently supported Windows versions, but warns that the code remains buggy and requires further development.
The release followed Naceri’s account of his departure from Microsoft, where he said he had worked in the UK and Germany. He claimed the company terminated his employment without a clear explanation and that a German labour court later upheld the dismissal after a prolonged legal dispute. Naceri also said the dispute had severely affected his mental health. He acknowledged that earlier claims Microsoft had taken legal action against him were fabricated.
SecurityWeek said it had contacted Microsoft for comment on BigDiskBuster, but no response was included in the report. The article does not report confirmed exploitation of the newly released code.