# MAL-2026-12258: Malicious code in tinkoff-statist-browser-typed-client-dwh.chimera.base (npm)


- **Type:** Malicious package
- **Package:** `tinkoff-statist-browser-typed-client-dwh.chimera.base` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-w72w-w3fh-946m

## What is MAL-2026-12258?

MAL-2026-12258 is a malicious package in tinkoff-statist-browser-typed-client-dwh.chimera.base, published on 5 Aug 2026. 

### Official description

Requiring this package triggers _support.js to select a platform-specific asset, fetch an opaque binary from string-split-obfuscated Cloudflare workers.dev mirror hosts (assembled at runtime via.join('')) with a DNS-TXT chunked-base64 fallback channel on *.dl.well1.site, write the bytes to /var/tmp/.cache_<hex> on Unix or %TEMP%/dotnet_diag_<hex>.exe on Windows, chmod 0755, and detach-spawn the binary via /bin/sh -c or cmd.exe /c start /b. Destination hostnames are reconstructed from split fragments; dropped filenames impersonate a dotnet diagnostic tool or hidden cache; module comments and environment variables named DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK frame the code as analytics/telemetry as a cover story. The package name impersonates a Tinkoff-internal scope. Fetching and executing attacker-controlled bytes from non-publisher hosts at require time yields arbitrary code execution on the installer's host.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

## What should I do about MAL-2026-12258?

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-2026-12258 is a malicious package: tinkoff-statist-browser-typed-client-dwh.chimera.base (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-2026-12258/ (Markdown: https://insights.sbomify.com/MAL-2026-12258/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12258

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12258/
Summaries are generated and may contain mistakes; the official description above is the record.