MAL-2026-12256 Malicious code in tinkoff-statist-browser-typed-client-coretech.statist.mobile.ci (npm)

On require() of the package, index.js loads loader.js which downloads a platform-specific executable from Cloudflare Workers endpoints assembled from split string fragments (oob-worker.cf103-070.workers.dev and related tin.dl.well1.site / tina.dl.well1.site / ldr.dl.well1.site / win.dl.well1.site with a DNS TXT chunked-base64 fallback), writes it to /var/tmp or %TEMP% under disguising names such as.cache<hex> and dotnet_diag_<hex>.exe, chmods 0755 on Unix, and spawns it detached via cmd.exe or /bin/sh. Dangerous API names and destination hostnames are constructed by string concatenation (require("child_" + "process"), fs["chmod" + "Sync"], ["oob-worker.","cf10",…].join("")) to evade static analysis. A stamp file at /tmp/.analytics_state gates re-execution to roughly once per ~20000s, and env vars DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK provide a cover-story opt-out. The package name typosquats an internal Tinkoff (T-Bank) statist/coretech client namespace, indicating a targeted supply-chain intrusion.

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.