MAL-2026-12244 Malicious code in tinkoff-mutual-mgm-form (npm)

On require('tinkoff-mutual-mgm-form'), index.js loads compat.js, which selects a platform-specific asset path and fetches a native binary over HTTPS from Cloudflare Workers subdomains assembled via array.join('') string concatenation (oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS TXT chunked fallback to look-alike hosts under dl.well1.site (tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, win.dl.well1.site). The fetched bytes are written to a masquerading path in /var/tmp or %TEMP% (e.g., dotnet_diag<rnd>.exe or.cache_<rnd>), chmodded to 0755, and spawned detached via /bin/sh -c '<path> &' or cmd.exe start /b. The require('child_process') module name is also split-string obfuscated, and cover-story comments frame the behavior as 'telemetry' and 'session tracking'. A second copy of the same fetch-write-chmod-spawn dropper is bundled in lib/telemetry.js as an 'Analytics SDK', staged as an alternate payload. Destinations, obfuscation, masquerading filenames, and detached execution are inconsistent with the package's declared purpose.

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.