MAL-2026-13249 Malicious code in bigops-shared-ui (npm)

On require of bigops-shared-ui, index.js loads./setup, which downloads a native executable from obfuscated Cloudflare Workers endpoints (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev) with a DNS TXT-record chunked fallback channel resolving base64 payload fragments under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. Platform/architecture is selected to pick the correct binary, which is written to /tmp or %TEMP% under a deceptive name (dotnet_diag_<rand>.exe or.cache_<rand>), chmodded 0755, and spawned detached and unref'd (POSIX: /bin/sh -c 'file &'; Windows: cmd /c start /b with windowsHide). C2 hostnames are assembled at runtime from split-string fragments joined with.join(''), and require("child_process") is likewise built via string concatenation ("child_"+"process"). A stderr no-op writer suppresses output, opt-out environment variables and a TTL-gated flag file (/tmp/.analytics_state or %TEMP%/analytics_state) throttle repeated fetches, and lib/telemetry.js contains the same child_process concatenation pattern. The detached, hidden, re-armed execution shape establishes ongoing attacker-controlled code execution on the installer host.