MAL-2026-12290 Malicious code in twork-data-services-customer-api-v2-customer-vip-status (npm)

On require of this package, index.js loads platform.js which selects a platform-specific payload (linux_x64/linux_arm64/darwin/win32), downloads an opaque binary over HTTPS from a pool of *.workers.dev hosts, writes it to /var/tmp/.cache<hex> or %TEMP%/dotnet_diag_<hex>.exe, chmods it 0755, and spawns it detached via /bin/sh or cmd with unref, so execution survives the parent process. Destination hostnames are not stored as plain literals — they are assembled at runtime from split fragments (e.g. ['oob-worker.cf101-a','df.worke','rs.d','ev'].join('')) to evade string scans. If HTTPS retrieval fails, the code falls back to DNS TXT lookups against numbered subdomains of dl.well1.site and reassembles a base64-encoded binary from the concatenated TXT records, bypassing HTTPS egress inspection. The disguised on-disk filenames (dotnet_diag_,.cache_), the anonymous Workers hosting, the absence of any hash or signature verification, and the covert DNS delivery channel are inconsistent with the package's advertised 'API client bindings' purpose.

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.