Architectural Collapse: How Extension Poisoning, Node Vulnerabilities, and Infrastructure Fog Enabled the GitHub Repository Breach

Enterprise perimeter defenses are fundamentally built on an obsolete assumption that the developer’s workstation is a secure, trusted anchor point. The massive security breach executed by the threat group TeamPCP , resulting in the exfiltration of 3,800 internal GitHub source code repositories , completely shattered this illusion. This was not a standalone exploit.