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.

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Source: google-open-source-security (d83c3b506a10b770a8c1f98d280262478cccc65708bb1066a72e0708dccaaf75)

This malicious package is part the IronWorm campaign. This campaign executes a malicious binary payload during installation via a preinstall hook. The payload is a Rust-built infostealer that targets developer environments, scanning for and harvesting credentials related to cloud providers, object storage, databases, source-control, package registries, and AI developer tools. It also targets cryptocurrency wallets, specifically injecting a malicious JavaScript hook into the Exodus desktop wallet to capture passwords and recovery phrases. Furthermore, the malware exhibits worm-like behavior by stealing GitHub and NPM credentials to push malicious updates to the victim's repositories and publish trojanized packages, and it uses an eBPF-based kernel rootkit to hide its processes and network connections on Linux systems.