Researcher Drops BigDiskBuster Zero-Day PoC That Blocks Microsoft Defender Updates
Researcher publishes unpatched BigDiskBuster PoC that can block Microsoft Defender signature and platform updates.
Researcher Abdelhamid Naceri published BigDiskBuster on September 19, an unpatched proof-of-concept with no CVE that can stop Microsoft Defender from installing platform and signature updates by filling free disk space. Defender keeps running, but its detection content can go stale. His earlier tools BlueHammer, RedSun, and UnDefend were exploited before Microsoft patched them; UnDefend was fixed in May as CVE-2026-45498, and that patch is not shown to cover this different method. No independent confirmation of BigDiskBuster has been reported.
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