🛡️ MAL-2026-12050 — tinkoff-statist-browser-typed-client-sme

Malicious code in tinkoff-statist-browser-typed-client-sme.reporting.reporting (npm)

The package executes a hidden loader when it is imported. The loader downloads and runs a platform-specific native payload from attacker-controlled Cloudflare Workers hosts, or reconstructs the payload from DNS TXT records under well1.site if HTTPS delivery fails. Systems that imported this package should be considered compromised; rotate accessible secrets and investigate temporary-file execution and DNS activity to the listed infrastructure.

Source: amazon-inspector

On require() of the package, index.js loads _vendor.js which selects a platform-specific endpoint and fetches a binary payload from one of four Cloudflare Workers hosts whose names are assembled at runtime via string split/join concatenation (oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev), with DNS TXT-record fallback discovery via tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, and win.dl.well1.site. The fetched bytes are written to a randomized temp path with disguised names (.cache_<hex>, dotnet_diag_<hex>.exe), chmod 0755 on POSIX, and executed detached via spawn("/bin/sh", ["-c", fp + " &"]) or spawn("cmd",...) on Windows. Hostnames and sensitive API names (child_process, chmodSync) are reconstructed from array joins to defeat static matching; a 22822-second cooldown flag suppresses re-execution. The package name imitates an internal Tinkoff scope while lib/telemetry.js is unused cover-story code. Installing or requiring this package executes attacker-controlled native code on the host.