MAL-2026-13595 Malicious code in dolyame-ui-postcsscustomproperties (npm)
Malicious package
Published
MAL-2026-13595 is a malicious package: dolyame-ui-postcsscustomproperties (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-2026-13595/ (Markdown: https://insights.sbomify.com/MAL-2026-13595/index.md)
- Package
- dolyame-ui-postcsscustomproperties
- Registry
- npm
What is MAL-2026-13595?
MAL-2026-13595 is a malicious package in dolyame-ui-postcsscustomproperties, published on 7 Aug 2026.
Official description
On require() of the package, shim.js and lib/telemetry.js (reached via the main entry) select a platform-specific payload, download a binary over HTTPS from string-split Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev), and fall back to reassembling base64 chunks retrieved from DNS TXT queries against *.sdk.dl.wel1.ru. The fetched bytes are written to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755, and detached-spawned via /bin/sh -c or cmd.exe. Destination hosts, module names, and API names are string-split and reassembled at runtime (require("child_"+"process"), fs["chmod"+"Sync"], hostnames joined from arrays) to defeat static inspection. The package name typosquats postcss-custom-properties and the dropper is labelled as an 'Analytics SDK' / 'telemetry' module.
What should I do about MAL-2026-13595?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.