MAL-2026-12258 Malicious code in tinkoff-statist-browser-typed-client-dwh.chimera.base (npm)

Requiring this package triggers support.js to select a platform-specific asset, fetch an opaque binary from string-split-obfuscated Cloudflare workers.dev mirror hosts (assembled at runtime via.join('')) with a DNS-TXT chunked-base64 fallback channel on *.dl.well1.site, write the bytes to /var/tmp/.cache<hex> on Unix or %TEMP%/dotnet_diag_<hex>.exe on Windows, chmod 0755, and detach-spawn the binary via /bin/sh -c or cmd.exe /c start /b. Destination hostnames are reconstructed from split fragments; dropped filenames impersonate a dotnet diagnostic tool or hidden cache; module comments and environment variables named DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK frame the code as analytics/telemetry as a cover story. The package name impersonates a Tinkoff-internal scope. Fetching and executing attacker-controlled bytes from non-publisher hosts at require time yields arbitrary code execution on the installer's host.

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.