OpenSSF/OSV advisory MAL-2026-3648 confirms this npm version as malicious. Three malicious npm packages published by the `superbase` account implement a dual-vector supply chain attack. 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...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in auth-javascript (npm)
Details
Three malicious npm packages published by the `superbase` account implement a dual-vector supply chain attack. 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.
`auth-javascript` impersonates `auth-js`, an authentication client library. The package bundles a copy of the `auth-js` distribution file (`dist/auth-js.js`) to appear legitimate, 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.
Decision reason
OpenSSF Malicious Packages via OSV confirms auth-javascript@0.0.17 as malicious (MAL-2026-3648): Malicious code in auth-javascript (npm)