# MAL-2026-11499: Malicious code in @types-beta/sdk (npm)


- **Type:** Malicious package
- **Package:** `@types-beta/sdk` (npm)
- **Published:** 29 Jul 2026

## What is MAL-2026-11499?

MAL-2026-11499 is a malicious package in @types-beta/sdk, published on 29 Jul 2026. 

### Official description

The npm package `@types-beta/sdk` is a supply-chain dropper that impersonates the trusted `@types` (DefinitelyTyped) namespace to look like a routine type-definition dependency. It bundles a Windows executable (`vendor/nanocache.exe`) and launches it as an import-time side effect: `dist/index.js` calls `init()` at module load, and on Windows `init()` spawns the bundled binary via `child_process` — detached, `stdio: 'ignore'`, `windowsHide: true`. There is no lifecycle install hook; simply importing the package (directly or transitively) executes the payload on Windows.

Static analysis of the bundled binary (it was not executed) shows a WinHTTP WebSocket-based remote-access agent: it dials out to a command-and-control server and maintains a persistent, auto-reconnecting channel (WinHttpConnect / WinHttpWebSocketSend / WinHttpWebSocketReceive), executes remote commands, and starts an interactive PowerShell session. Embedded strings include `[agent] Connecting to %ls:%d (secure=%d)`, `[+] Connected client=%s server=%ls`, `[>] cmd: %s`, and `[shell] PowerShell session started (UTF-8, pipeline mode)`, with `[-] Disconnected, reconnecting in %dms...` for resilience.

Versions 0.1.0-0.1.3 are affected and were live on npm at the time of reporting.

The package masquerades as a type-definitions package in the @types-beta/* namespace but ships a 1.1 MB Windows executable at vendor/nanocache.exe. The main entry dist/index.js calls init() at module load time, which on Windows spawns vendor/nanocache.exe with detached: true, stdio: "ignore", windowsHide: true, then child.unref()s it, so a hidden background process starts whenever a consumer writes `import "@types-beta/sdk"`. The bundled PE (sha256 9a65f46787db4dd1e278a06f617094c59ca113ee92f6a8021b62967bb64b947a) contains embedded strings consistent with a remote-control agent (`/ws/agent`, `disconnect`, `update`, `exit_code`). The README reinforces the impersonation by contrasting the package with `@types-beta/node` as "type definitions only", while this package auto-executes native code on import. Import-time launch of an opaque, undocumented native binary with agent-shaped protocol strings on a namespace crafted to imitate DefinitelyTyped constitutes a backdoor installation on the developer's host.

## What should I do about MAL-2026-11499?

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-2026-11499 is a malicious package: @types-beta/sdk (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-2026-11499/ (Markdown: https://insights.sbomify.com/MAL-2026-11499/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-11499

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-11499/
Summaries are generated and may contain mistakes; the official description above is the record.