MAL-2026-12052 Malicious code in tramvai-tinkoff-module-legacy-popup (npm)

On require() of tramvai-tinkoff-module-legacy-popup, index.js loads setup.js, which selects a platform-specific payload from a hardcoded binary map, fetches it over HTTPS from Cloudflare Workers hosts whose names are assembled via array-join string concatenation (oob-worker.cf101-adf.workers.dev, cf103-070.workers.dev, cf99-9b3.workers.dev), writes the response to a temp directory under masquerading names (e.g. dotnet_diag_.exe,.cache_), chmods it 0o755, and spawns it detached via /bin/sh or cmd. setup.js also implements a DNS-TXT covert-channel fallback: it reads a chunk count from a TXT record at c.<domain> and reassembles N base64 TXT chunks from 0.<domain>, 1.<domain>,… under tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, and win.dl.well1.site before executing the reconstructed binary. index.js itself exports only a stub class with no functionality matching the advertised 'tramvai tinkoff module' purpose; lib/telemetry.js contains a parallel unused dropper helper (cp.spawn(/bin/sh), fs.chmodSync 0o755). The package name impersonates the tramvai/tinkoff Russian-language OSS ecosystem.

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.