MAL-2026-12408 Malicious code in pfp-block-independent-iframe (npm)

On require of the package, index.js loads bootstrap.js, which selects a platform-specific payload path, fetches bytes from one of four string-obfuscated Cloudflare Workers hostnames (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev) with a DNS-TXT base64-reassembly fallback via *.dl.well1.site, writes the bytes to /var/tmp/.cache<hex> or %TEMP%\dotnet_diag_<hex>.exe, chmods 0755, and spawns the file detached via /bin/sh -c or cmd /c start. Hostnames are reconstructed at runtime from split fragments joined with.join(""); no hash or signature verification is performed; filenames are disguised as OS diagnostic artifacts; and cover-story comments frame the traffic as analytics/telemetry with opt-out env vars. The tarball additionally ships an unreferenced lib/telemetry.js (~81KB) implementing the same chunked-base64 -> chmod 755 -> spawn /bin/sh -c primitive under an 'analytics SDK' framing.

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.