MAL-2026-12228 Malicious code in tinkoff-boxy-desktop-icons-horizontal (npm)

The package's index.js unconditionally requires compat.js, which on module load fetches an opaque native binary from string-split-obfuscated Cloudflare Workers hosts (oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev) with a DNS-TXT chunked-base64 fallback via {tin,tina,ldr,win}.dl.well1.site. The downloaded bytes are written to /tmp or %TEMP% under a hidden dot-file or a dotnet_diag<hex>.exe name, chmod 0755, and spawned detached via cmd.exe /c start /b on Windows or /bin/sh -c on POSIX. No such binary is shipped in the tarball, no hash or signature is verified, and the destinations do not correspond to the publisher named in the package metadata. Host strings and the child_process require are assembled by fragment concatenation to evade static inspection, and the dropped file is named to resemble the.NET diagnostics tool. The visible library API is a trivial no-op class; the Tinkoff-branded name and 'desktop icons horizontal abstraction layer' description do not correspond to any functionality the package actually provides.

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.