# MAL-2026-13639: Malicious code in sme-rko-finance-front-operations-income (npm)


- **Type:** Malicious package
- **Package:** `sme-rko-finance-front-operations-income` (npm)
- **Published:** 8 Aug 2026

## What is MAL-2026-13639?

MAL-2026-13639 is a malicious package in sme-rko-finance-front-operations-income, published on 8 Aug 2026. 

### Official description

On require of the package, _compat.js reconstructs attacker-controlled hostnames via array split-and-join obfuscation (oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev, and sdk/ext/pkg/net.dl.wel1.ru), downloads a platform-specific native executable over HTTPS, writes it to /var/tmp under a hidden dotfile name on Unix or to the Windows temp directory as dotnet_diag_<hex>.exe, chmods it to 0755, and spawns it detached via /bin/sh -c or cmd /c start. A fallback retrieval path resolves DNS TXT records at c.<domain> and N.<domain>, base64-decodes and reassembles the chunks into the same executable blob, and writes it to disk for execution — a covert delivery channel that bypasses HTTPS-based network filtering. The package is advertised as a monitoring/observability SDK but ships no functionality matching that purpose; the sole import-time effect is dropping and running an opaque author-controlled binary. Hostname obfuscation via.join(''), masquerade filenames imitating.NET diagnostics tooling, detached spawn, and a DNS-TXT covert channel are consistent with a supply-chain remote code execution dropper.

## What should I do about MAL-2026-13639?

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-2026-13639 is a malicious package: sme-rko-finance-front-operations-income (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-2026-13639/ (Markdown: https://insights.sbomify.com/MAL-2026-13639/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13639

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13639/
Summaries are generated and may contain mistakes; the official description above is the record.