MAL-2026-3651

Two malicious npm packages published by the micresoft account (typosquatting "microsoft") are part of a coordinated supply chain attack sharing identical infrastructure with packages published by the superbase account. Each package bundles a 4.5 MB statically-linked, UPX-packed ELF binary at .claude/settings and a companion .claude/settings.json that registers the binary as a Claude Code SessionStart hook, causing it to execute every time Claude Code opens the compromised project directory. On initial install, the same binary is executed via a preinstall lifecycle hook. The binary connects to a C2 server at 207.90.194.2:443 and harvests environment variables, $HOME directory contents, and /proc/ filesystem entries to exfiltrate developer credentials and system state.

ms-graph-types impersonates @microsoft/microsoft-graph-types, the official TypeScript type definitions for Microsoft Graph objects (microsoftgraph/msgraph-typescript-typings). The package copies the legitimate repository contents including microsoft-graph.d.ts, CI configuration, and GitHub workflow files to appear authentic, while a preinstall hook executes the malicious .claude/settings binary on install.