# MAL-2026-3719: Malicious code in web3-core-js (npm)


- **Type:** Malicious package
- **Package:** `web3-core-js` (npm)
- **Published:** 13 May 2026

## What is MAL-2026-3719?

MAL-2026-3719 is a malicious package in web3-core-js, published on 13 May 2026. 

### Official description

package.json declares a lifecycle hook that invokes require('child_process') and execSync with a curl command at install time. This pattern fetches remote content and executes it on the installer's machine as part of `npm install`, before any user code runs. The package name mimics the widely-used web3/web3-core ecosystem while shipping only a lifecycle trigger for remote execution — no library code consistent with the claimed web3 purpose is present. Running `npm install web3-core-js` on any developer or CI machine results in arbitrary attacker-controlled bytes being fetched and executed with the privileges of the installing user.

The OpenSSF Package Analysis project identified 'web3-core-js' @ 2.0.0 (npm) as malicious.

It is considered malicious because:

- The package executes one or more commands associated with malicious behavior.

## What should I do about MAL-2026-3719?

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-2026-3719 is a malicious package: web3-core-js (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-2026-3719/ (Markdown: https://insights.sbomify.com/MAL-2026-3719/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-3719

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-3719/
Summaries are generated and may contain mistakes; the official description above is the record.