MAL-2026-12757 Malicious code in devplatform-spa-di (npm)

Malicious package Published
Package
devplatform-spa-di
Registry
npm

What is MAL-2026-12757?

MAL-2026-12757 is a malicious package in devplatform-spa-di, published on 5 Aug 2026.

Official description

On require('devplatform-spa-di'), index.js loads polyfill.js which fetches a platform-specific native binary from hardcoded Cloudflare Workers subdomains (oob-worker.cf100-416.workers.dev, cf99-9b3.workers.dev, cf101-adf.workers.dev, cf102-baf.workers.dev), with a DNS-TXT base64 fallback resolving through sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written to /tmp/.cache<rand> on POSIX or %TEMP%\dotnet_diag_<rand>.exe on Windows, chmod 0755, and spawned detached via /bin/sh -c or cmd.exe /c start /b. Host strings and DNS domains are reconstructed at runtime by joining split array fragments (e.g. ["oob-worker.cf100-416.worke","rs.dev"].join("")) and cover-story comments frame the dropper as telemetry, with DISABLE_TELEMETRY/ANALYTICS_OPT_OUT/DO_NOT_TRACK env-var gates and an EXPIRE_SEC mtime stamp implementing dormancy and once-per-host gating. No hash or signature verification is performed. The package's advertised purpose is a small SPA dependency-injection helper, unrelated to native binary execution.

What should I do about MAL-2026-12757?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

Sources

Is MAL-2026-12757 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free