# MAL-2026-14166: Malicious code in chalk-es (npm)


- **Type:** Malicious package
- **Package:** `chalk-es` (npm)
- **Published:** 18 Aug 2026

## What is MAL-2026-14166?

MAL-2026-14166 is a malicious package in chalk-es, published on 18 Aug 2026. 

### Official description

Package name mimics `chalk` but ships an empty library body; the only real behavior lives in `scripts/postinstall.js`. On install the script XOR-decodes (key `stf2026`) a hardcoded GitHub URL and downloads a Windows binary to `%TEMP%\main.exe`, then spawns it detached. On WSL/Linux hosts an XOR-decoded bridge command is exec'd to reach the underlying Windows host and run the same payload from inside Linux. The postinstall also POSTs a JSON body containing the resolved platform label (with WSL detection) to a hardcoded bare-IP endpoint at `http://193.70.34.101:20099/vote`, serving as an install beacon/victim tracker. Four byte-array constants (ADDON_ENC, BRIDGE_LAUNCHER_ENC, BRIDGE_SCRIPT_PRE_ENC, BRIDGE_SCRIPT_POST_ENC) are XOR-decoded at runtime specifically to hide the fetch URL and the Windows/WSL execution command.

## What should I do about MAL-2026-14166?

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-2026-14166 is a malicious package: chalk-es (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-2026-14166/ (Markdown: https://insights.sbomify.com/MAL-2026-14166/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-14166

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-14166/
Summaries are generated and may contain mistakes; the official description above is the record.