MAL-2026-12234 Malicious code in tinkoff-boxy-mobile-documents (npm)

On require of the package, index.js loads./platform.js, which selects a per-platform payload path, fetches an unsigned binary over HTTPS from string-split Cloudflare Workers subdomains (oob-worker.cf103-070.workers.dev, cf102-baf.workers.dev, cf101-adf.workers.dev, cf100-416.workers.dev) assembled via array joins, with a DNS TXT covert-channel fallback under *.dl.well1.site (also string-split). The fetched bytes are written to /tmp or %TEMP% under decoy names (analytics_state, dotnet_diag,.cache_), chmodded to 0755, and spawned detached via /bin/sh -c or cmd /c start. Hostnames and resolver domains are obfuscated by array joins and child_process is referenced as require('child_' + 'process'), and the loader is framed with 'analytics/telemetry' comments and DISABLE_TELEMETRY / ANALYTICS_OPT_OUT opt-out gates as cover. lib/telemetry.js contains a duplicate dropper implementation (base64 chunk assembly, cp.spawn('/bin/sh', ['-c', filePath + ' &']), chmod 0755 via computed property) bundled as an alternate loader. The package name impersonates a Tinkoff-branded mobile-documents component.

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.