MAL-2026-12266 Malicious code in tinkoff-statist-browser-typed-client-leasing.admin.events (npm)

The package's main entry index.js require()s helpers.js, whose top-level bootstrap runs on load. It detects platform and architecture, fetches a native binary from one of several string-split-obfuscated hosts under *.workers.dev (with a DNS-TXT base64 fallback via *.well1.site subdomains), writes the payload to a disguised path such as /var/tmp/.cache<hex> or %TEMP%/dotnet_diag_<hex>.exe, chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe /c start /b. Hostnames and the child_process require target are assembled from array.join fragments to evade string scanning, and a stamp-file check skips re-execution on subsequent installs. A second parallel dropper implementation is bundled as lib/telemetry.js (~81KB) using the same transport, DNS failover, chmod 755, and /bin/sh -c spawn pattern. The package name is a typosquat of an internal Tinkoff namespace with no legitimate purpose visible in the tarball.

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.