devplatform-humanize-network-error @35.3.8

Summary

devplatform-humanize-network-error@35.3.8 advertises itself as a network-error humanizing utility, but on require() its index.js unconditionally loads _adapter.js, which fetches a platform-specific native binary over HTTPS from Cloudflare Workers hosts assembled at runtime from string fragments (oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), writes it to /tmp/.cache_<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe . No hash or signature verification is performed and the payload is unrelated to the package's stated purpose. If the HTTPS fetch returns less than 1000 bytes, a fallback DNS-TXT covert channel reassembles a base64-encoded payload from TXT records under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru (queried as c.<domain> plus per-index sub-labels) and executes it identically. Destination hostnames are reconstructed from .join("") fragments and dropped artifacts are named to masquerade as telemetry/diagnostic files (.analytics_state,.cache_<hex>, dotnet_diag_<hex>.exe), with comments framing the drop as analytics. A sibling lib/telemetry.js (~80 KB) shipped in the same tarball replicates the same HTTPS+DNS discovery, detached shell spawn, chmod 0755, and base64 chunk reassembly primitives but is not currently referenced by the entry graph.

Source: amazon-inspector (3d18ba9f3689dbc03127a3d82ffe0a6a2a15edf3e7f58b7ca9322499b2b68197)