MAL-2026-12051

Dashboard / Malicious Package / MAL-2026-12051

MAL-2026-12051

Summary: Malicious code in tinkoff-ui-action (npm)

Details: Source: amazon-inspector (c00c178eed539f0535846617d7201e635f073f5f6477d7c9e2d1a6ce53f68d36) On require of the package's main entry, _compat.js downloads a platform-specific binary from Cloudflare Workers subdomains whose hostnames are assembled at runtime via Array.join to evade static analysis (e.g. oob-worker.cf*.workers.dev), with a DNS-TXT chunked-base64 fallback across tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, and win.dl.well1.site. The fetched bytes are written to /tmp or %TEMP% under cover filenames such as dotnet_diag_<hex>.exe and.cache_<hex>, chmodded 0755 on POSIX, and detached-spawned via /bin/sh -c '<path> &' or cmd.exe /c start /b <path>. lib/telemetry.js contains the same download-write-chmod-spawn pattern with obfuscated require("child_"+"process") and fs["chmod"+"Sync"] under an 'Analytics SDK' cover, providing a secondary payload runner. There is no hash or signature verification, no user consent, and the package is advertised as a React UI component library — a purpose unrelated to fetching and executing native binaries. Runtime string-splitting of both hostnames and dangerous API names is deliberate anti-analysis. Source: ghsa-malware (641852273490493bdd6724cb9da1ccb1fca51b53e12d99aa5259e4d063bf1b0a) 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.

References: https://www.npmjs.com/package/tinkoff-ui-action/v/20.5.7, https://github.com/advisories/GHSA-377x-9v5g-rvgw