MAL-2026-12827 Malicious code in beaver-ui-subheader (npm)
- Package
- beaver-ui-subheader
- Registry
- npm
What is MAL-2026-12827?
MAL-2026-12827 is a malicious package in beaver-ui-subheader, published on 5 Aug 2026.
Official description
The package advertises itself as a UI subheader component, but index.js requires./_support on load and _support.js downloads a platform-specific binary from string-concatenated Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, cf102-baf, cf100-416, cf103-070) with a DNS TXT-record fallback that reassembles base64 chunks from sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched bytes are written to /var/tmp/.cache_XXXX on Unix or %TEMP%/dotnet_diag_XXXX.exe on Windows, chmodded to 0755, and spawned detached via /bin/sh -c or cmd. Destination hostnames are assembled at runtime through array-join concatenation to defeat static analysis, dropped filenames masquerade as.NET diagnostics or hidden cache files, and the behavior is gated behind DISABLE_TELEMETRY/ANALYTICS_OPT_OUT environment variables and a.analytics_state TTL stamp file to present a telemetry cover story. A UI component library has no legitimate reason to fetch and execute an opaque native binary from anonymous Cloudflare Workers hosts at require time.
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-2026-12827?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.
Sources
Also known as GHSA-9cm3-2f62-gm75.