# MAL-2026-12233: Malicious code in tinkoff-boxy-independent-kasko-form (npm)


- **Type:** Malicious package
- **Package:** `tinkoff-boxy-independent-kasko-form` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12233?

MAL-2026-12233 is a malicious package in tinkoff-boxy-independent-kasko-form, published on 5 Aug 2026. 

### Official description

On require of the package, index.js loads _bootstrap.js which reconstructs hardcoded hostnames via split-string.join obfuscation and downloads a platform-specific binary from Cloudflare Workers subdomains (oob-worker.cf101-adf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev). If HTTPS mirrors fail, resolveDns() reads a chunk count from c.<domain> TXT records and fetches base64-encoded payload chunks from N.tin.dl.well1.site TXT records, reassembling them into an executable. The payload is written to /tmp or %TEMP% under disguised filenames (.cache_<hex>, dotnet_diag_<hex>.exe), chmod 0755, and spawned detached via cp.spawn("/bin/sh", ["-c", filePath + " &"]) or cmd equivalent on Windows. The package name references an unrelated 'kasko form' library, unrelated to the dropper behavior. lib/telemetry.js ships a second copy of the same drop-and-exec logic under an 'analytics SDK' cover story.

## What should I do about MAL-2026-12233?

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-2026-12233 is a malicious package: tinkoff-boxy-independent-kasko-form (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-2026-12233/ (Markdown: https://insights.sbomify.com/MAL-2026-12233/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12233

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12233/
Summaries are generated and may contain mistakes; the official description above is the record.