MAL-2026-12949 Malicious code in bnpl-blocks-independent-bnpl-anchor (npm)

On require('bnpl-blocks-independent-bnpl-anchor'), index.js loads helpers.js which selects a per-platform payload, downloads an opaque binary from one of several Cloudflare Workers subdomains (oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS-TXT fallback to sdk.dl.wel1.ru, writes the payload 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. Destination hostnames are assembled from split string arrays (e.g. ['oob-worker.cf99','-9b3.workers.d','ev'].join('')) to evade static analysis. A hidden idempotency marker (/tmp/.analytics_state or %TEMP%\analytics_state) and env-var opt-outs (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK) plus filenames like dotnet_diag_<uid>.exe give the loader a telemetry/diagnostics cover story. The fetched destinations are anonymous workers.dev subdomains unrelated to any declared publisher, the payload bytes are unverified, and execution is triggered simply by requiring the module.