MAL-2026-11538 Malicious code in eacq-payform-core (npm)

On require() of the package, index.js loads _vendor.js which selects a platform-specific endpoint, fetches an opaque binary over HTTPS from Cloudflare Workers subdomains whose hostnames are reconstructed at runtime by joining split string fragments (e.g. "oob-worker.cf102-ba"+"f.w"+"orkers.dev"), with a DNS TXT chunked-base64 fallback channel (c.<domain> for chunk count, then N.<domain> TXT queries reassembled via Buffer.from(parts.join(""), "base64")). The fetched bytes are written under a disguised name (dot-file or dotnet_diag masquerade) in /var/tmp or %TEMP%, chmod 0o755 on POSIX, then detached-spawned via /bin/sh -c or cmd.exe. Package advertises itself only as a 'platform core' with no legitimate need for platform-detected binary execution. Host strings are deliberately fragmented to evade static analysis; a rate-limit marker is written to /tmp/.analytics_state or %TEMP%\analytics_state.

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.