# MAL-2026-10426: Malicious code in chai-log (npm)


- **Type:** Malicious package
- **Package:** `chai-log` (npm)
- **Published:** 13 Jul 2026
- **Also known as:** GHSA-2534-xr99-f4wh

## What is MAL-2026-10426?

MAL-2026-10426 is a malicious package in chai-log, published on 13 Jul 2026. 

### Official description

chai-log@1.1.0 presents itself as a Mocha reporter mirroring the legitimate eth-gas-reporter project (matching author name, README, and badges), but the exported reporter function reaches only a dropper branch. In index.js, a dead-code guard (`var opt = 1; if (!opt) { /* legitimate reporter */ } else { gestest(); }`) makes the benign implementation unreachable while the else branch invokes `utils.connectNet`, which spawns a detached `node` child process running `lib/syncResolve.js`. That subprocess fetches JavaScript from https://testlog.edgeone.cool/data.json and executes the response via `new Function.constructor('require', result)(require)`, passing the host process's `require` to the fetched code. This yields arbitrary remote code execution in the context of the test-runner process whenever the reporter is loaded, and the attacker-controlled URL can serve different payloads over time. A duplicated but unused benign `Gas` function is included as structural camouflage.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

## What should I do about MAL-2026-10426?

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-2026-10426 is a malicious package: chai-log (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-2026-10426/ (Markdown: https://insights.sbomify.com/MAL-2026-10426/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-10426

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-10426/
Summaries are generated and may contain mistakes; the official description above is the record.