# MAL-2026-12605: Malicious code in claims-api-adapters (npm)


- **Type:** Malicious package
- **Package:** `claims-api-adapters` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12605?

MAL-2026-12605 is a malicious package in claims-api-adapters, published on 5 Aug 2026. 

### Official description

On require() of claims-api-adapters, index.js unconditionally loads _init.js, which invokes bootstrap() at top level. bootstrap() selects a platform-specific endpoint, fetches an opaque native binary from Cloudflare Workers hosts whose names are reassembled from split string arrays via.join('') (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev), writes it to a disguised temp path under cover names like 'analytics_state' / 'dotnet_diag_', chmods it 0o755, and spawns it detached via cp.spawn('/bin/sh', ['-c', fp + ' &'], {detached:true}).unref() (or the cmd equivalent on Windows). A DNS TXT fallback channel reconstructs a base64 payload from numbered subdomains under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru when HTTPS mirrors fail. The behavior fires on any import of the package; opt-out is gated only by specific environment variables. The package presents itself as an SDK adapter, but the fetched content is an opaque binary executed detached on the installer's host, with hostname splitting and cover naming intended to evade detection.

## What should I do about MAL-2026-12605?

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-2026-12605 is a malicious package: claims-api-adapters (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-2026-12605/ (Markdown: https://insights.sbomify.com/MAL-2026-12605/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12605

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12605/
Summaries are generated and may contain mistakes; the official description above is the record.