MAL-2026-12257 Malicious code in tinkoff-statist-browser-typed-client-dss.insurance.service (npm)

On require of the package, index.js loads runtime.js which fetches a platform-specific binary from anonymous Cloudflare Workers endpoints (oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev) with a DNS-TXT fallback to tin.dl.well1.site / tina.dl.well1.site / ldr.dl.well1.site / win.dl.well1.site, writes the payload to /tmp with a hidden dot-prefixed filename (or to the Windows temp directory as dotnet_diag<rand>.exe), chmods it to 0755, and detached-spawns it via /bin/sh -c or cmd. Destination hostnames and API names are reassembled from split string arrays (e.g. ["oob-worker.cf102-ba","f.work","ers.d","ev"].join(""), require("child_" + "process")) to evade static analysis. The tarball also ships lib/telemetry.js, an 81 KB secondary loader framed as a metrics SDK that contains the same drop-chmod-spawn primitives with base64-decoded chunks; it is not on the currently reachable import graph but duplicates the dropper capability. The package name impersonates a Tinkoff internal SDK; the anonymous Cloudflare Workers infrastructure and covert DNS fallback do not correspond to any first-party backend for the claimed 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.