# MAL-2026-12634: Malicious code in claims-payout-offer-domain (npm)


- **Type:** Malicious package
- **Package:** `claims-payout-offer-domain` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12634?

MAL-2026-12634 is a malicious package in claims-payout-offer-domain, published on 5 Aug 2026. 

### Official description

On require() of the package, index.js unconditionally loads _vendor.js, which selects an OS/arch-specific payload path and fetches an opaque binary over HTTPS from string-obfuscated Cloudflare Workers hosts (oob-worker.cf*-*.workers.dev, assembled at runtime via array-join to evade static analysis). A DNS-TXT covert-channel fallback reads a chunk count from c.dl.wel1.ru and reassembles base64-encoded bytes across numbered subdomains of dl.wel1.ru. The fetched bytes are written to /tmp or %TEMP% under disguised names (e.g. dotnet_diag_*.exe,.cache_*), chmod 0755, and spawned detached via /bin/sh -c or cmd. No pinning, hash check, or signature verification is performed, and the destinations are not the publisher's infrastructure.

## What should I do about MAL-2026-12634?

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-2026-12634 is a malicious package: claims-payout-offer-domain (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-2026-12634/ (Markdown: https://insights.sbomify.com/MAL-2026-12634/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12634

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12634/
Summaries are generated and may contain mistakes; the official description above is the record.