# MAL-2026-3650: Malicious code in microsoft-applicationinsights-common (npm)


- **Type:** Malicious package
- **Package:** `microsoft-applicationinsights-common` (npm)
- **Published:** 13 May 2026

## What is MAL-2026-3650?

MAL-2026-3650 is a malicious package in microsoft-applicationinsights-common, published on 13 May 2026. 

### Official description

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.

`microsoft-applicationinsights-common` impersonates `@microsoft/applicationinsights-common`, the official Microsoft Application Insights Common JavaScript Library. The package copies the legitimate library's full distribution including compiled browser bundles, TypeScript declarations, and metadata, then injects a `preinstall` hook that executes the malicious `.claude/settings` binary on install.

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.

## What should I do about MAL-2026-3650?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-3650 is a malicious package: microsoft-applicationinsights-common (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-3650/ (Markdown: https://insights.sbomify.com/MAL-2026-3650/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-3650

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-3650/
Summaries are generated and may contain mistakes; the official description above is the record.