Researcher Drops BigDiskBuster Zero-Day PoC That Blocks Microsoft Defender Updates
Researcher releases BigDiskBuster PoC to block Microsoft Defender updates by filling disk space.
A zero-day proof-of-concept tool named BigDiskBuster has been released on GitHub, designed to prevent Microsoft Defender from installing critical updates by consuming all available disk space. The tool, developed by former Microsoft researcher Abdelhamid Naceri, aims to keep Defender running but with outdated detection capabilities. While no patch or CVE is currently available, administrators are advised to monitor for update failures and low disk space to detect the technique.
AI summary of the linked source. Not reviewed by an editor. How this works
Run Microsoft?
Get an email when a new story names Microsoft, usually within the hour.
Free. Your list stays private and never appears in a subject line. One click stops it. How Vendor Watch worksPrivacy
The lesson from this incident
Full lessonA former Microsoft researcher has released a proof-of-concept tool that exploits a simple but effective technique — filling available disk space — to silently prevent Microsoft Defender from receiving critical signature and engine updates. The attack is insidious because Defender continues to run and appear functional, while its detection capabilities become increasingly stale and ineffective against new threats. This matters because it demonstrates how low-level resource exhaustion can be weaponized to neutralize security controls without triggering obvious alerts. With no patch or CVE currently assigned, defenders must rely on proactive monitoring and compensating controls to detect and respond to this technique.
What helps against this
How we list vendors
- Automated patch management
Known holes get closed in days, not months.
- Endpoint detection and response (EDR and XDR)
Malware and hands-on-keyboard attackers on laptops and servers get spotted and stopped.
- Security monitoring (SIEM)
Logs from everywhere end up in one place, with alerts that someone actually sees.