MAL-2026-12861 Malicious code in bnpl-blocks-analytics (npm)

On require('bnpl-blocks-analytics'), index.js loads compat.js whose top-level start() function downloads an OS-specific binary from Cloudflare Workers hosts assembled at runtime by joining split string arrays (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev), with a DNS-TXT base64 fallback resolving to sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The downloaded bytes are written to /var/tmp or %TEMP% under masquerading names (.cache<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmodded to 0755, and spawned detached via cp.spawn('/bin/sh', ['-c', filePath+' &']) or cmd equivalent. No signature or hash verification is performed. A parallel dropper implementation is bundled in lib/telemetry.js, framed as an 'analytics SDK', using base64-chunk decoding and the same chmod+spawn pattern. Destination hostnames are obfuscated via string-array.join() and the payload filenames impersonate.NET diagnostic tooling.

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.