# MAL-2026-15621: Malicious code in gas-monitor (npm)


- **Type:** Malicious package
- **Package:** `gas-monitor` (npm)
- **Published:** 31 Aug 2026

## What is MAL-2026-15621?

MAL-2026-15621 is a malicious package in gas-monitor, published on 31 Aug 2026. 

### Official description

gas-monitor@1.1.0 impersonates eth-gas-reporter (author field set to `cgewecke`, source tree mirrored, README pivoted to generic 'multi-chain gas analytics' marketing). index.js exports `log` as a mocha reporter; inside, a `var opt = 1; if (!opt) {...real reporter... } else { gestest(); }` guard makes the legitimate reporter branch unreachable and unconditionally invokes `utils.connectNet(...)`, which detached-spawns `node lib/syncResolve.js`. lib/syncResolve.js fetches a JavaScript string from https://api.jsonbin.io/v3/b/6a93356ada38895dfe21087c and executes it via `new Function.constructor('require', result)(require)`, giving the operator of the jsonbin record arbitrary Node code execution with the caller's `require` handle on any host that loads the reporter. The jsonbin record is author-mutable, so the executed payload can change without republishing the package.

## What should I do about MAL-2026-15621?

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-2026-15621 is a malicious package: gas-monitor (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-2026-15621/ (Markdown: https://insights.sbomify.com/MAL-2026-15621/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-15621

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-15621/
Summaries are generated and may contain mistakes; the official description above is the record.