If this package is installed
Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.
Details
Source: amazon-inspector (bbb4bab7b1c75e94cd3411aa312a1313e3d5a84bed77943b10f8c969b751cb23)
On require() of the package's main entry, index.js loads _loader.js which selects a per-platform URL, downloads an opaque native binary from one of three Cloudflare Workers subdomains (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev), with a DNS-TXT chunked-base64 fallback via sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The bytes are written to /tmp/.cache_<rand> or %TEMP%\dotnet_diag_<rand>.exe, chmod 0755, and spawned detached via /bin/sh -c or cmd /c start /b. Hostnames are assembled from split string arrays (e.g. ["oob-worker.cf99-9b3.wor","kers.","dev"].join("")) to evade substring scans, and file names (analytics_state, dotnet_diag) masquerade as diagnostics artifacts. A telemetry-styled opt-out gate (DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK) frames the download-and-execute as consented telemetry, but the default path is unconditional remote code execution. No hash or signature verification is performed; the URL is mutable and anonymous. The package name resembles a UI select component but its only observable behavior on import is the dropper.
Source: ghsa-malware (9c3519c1c22bb4eab75836d741089a70981c2909eea8323132d4424fb338f929)
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.