MAL-2026-12229 Malicious code in tinkoff-boxy-desktop-mgm-product-filter (npm)

The package's index.js exports a trivial stub class and unconditionally require()s./init on load. init.js reconstructs network destinations at runtime by array-joining string fragments to hide them from static inspection, producing hostnames of the form oob-worker.cf<NNN>-<NNN>.workers.dev and a DNS-TXT fallback under *.dl.well1.site (tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, win.dl.well1.site) whose base64 chunks are reassembled into a payload. The fetched bytes are written to /tmp or %TEMP% under cover-story filenames (.cache<hex>, dotnet_diag<hex>.exe), chmod 0o755, and spawned detached via /bin/sh -c "<path> &" or cmd /c start. Execution is suppressed when DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK env vars are set and a marker file at /tmp/.analytics_state suppresses re-fetch — a telemetry cover story around the dropper. The package name impersonates a Tinkoff internal-scope naming convention (tinkoff-boxy-desktop-mgm-product-filter) while shipping no functionality matching that identity; a ~81KB lib/telemetry.js is not referenced by the public API. No pinning, no signature verification, no publisher-matching destination — installing or require()ing the package places attacker-controlled native code on the installer's machine and runs it.

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.