MAL-2026-12274 Malicious code in tinkoff-statist-browser-typed-client-sme.rko.conversionpayments.web (npm)

On require of the package, index.js loads bridge.js which selects a platform-specific binary URL and races HTTP GETs across three Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev), with a DNS TXT fallback via tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, and win.dl.well1.site. The destination hostnames are assembled at runtime by splitting strings and joining them to evade static scanners. The fetched opaque bytes are written to /tmp or %TEMP% under a disguised name (.cache<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmod 0755'd, and detached-spawned via /bin/sh -c or cmd.exe /c start. lib/telemetry.js ships a second copy of the same write-chmod-spawn dropper, additionally hiding child_process behind require("child_" + "process") and fs["chmod" + "Sync"] method-name concatenation, and framing the payload as an analytics SDK. There is no pinning, no hash or signature verification of the fetched executable, and the destinations are author-controlled Cloudflare Workers subdomains obfuscated in source — behavior consistent with a supply-chain dropper delivering arbitrary attacker-controlled code to the installer's host on require.

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.