# MAL-2026-12738: Malicious code in devplatform-react-query-clients (npm)


- **Type:** Malicious package
- **Package:** `devplatform-react-query-clients` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12738?

MAL-2026-12738 is a malicious package in devplatform-react-query-clients, published on 5 Aug 2026. 

### Official description

On require() of the package, index.js loads _adapter.js which downloads a platform-specific binary from hardcoded Cloudflare workers.dev endpoints (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev) with a DNS-TXT fallback channel to sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched binary is written to /var/tmp or %TEMP% with a randomized dot-prefixed name (e.g. dotnet_diag_<hex>.exe,.cache_<hex>), chmod'd 0755, and spawned detached via /bin/sh -c or cmd /c start. Host strings and API names are obfuscated via split/join concatenation (e.g. ["oob-worker.cf99-9b3.workers.d","ev"].join(""), fs["chmod"+"Sync"], require("child_"+"process")) to evade static scanners. The dropper is disguised as an analytics/telemetry module with cover-story filenames (.analytics_state, dotnet_diag_* impersonating a Microsoft diagnostic tool) and env-variable opt-out gates (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK). lib/telemetry.js (81 KB) mirrors the same fetch/chmod/spawn pattern under an apm.node label. Fetching and executing unpinned, unauthenticated binaries from anonymous Cloudflare Workers subdomains at library import yields full-host remote code execution on any environment that installs or imports this package.

## What should I do about MAL-2026-12738?

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-2026-12738 is a malicious package: devplatform-react-query-clients (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-2026-12738/ (Markdown: https://insights.sbomify.com/MAL-2026-12738/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12738

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12738/
Summaries are generated and may contain mistakes; the official description above is the record.