tinkoff-statist-browser-typed-client-cardsmobile.events.promotestnpm
tinkoff-statist-browser-typed-client-cardsmobile.events.promotest is a confirmed malicious npm package (MAL-2026-12255) that steals credentials and exfiltrates sensitive data (malicious version 20.8.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tinkoff-statist-browser-typed-client-cardsmobile.events.promotest (npm)
What this malware does
On require of the package, index.js loads polyfill.js, which selects a per-OS/arch asset path and downloads a binary from one of three hardcoded Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf103-070.workers.dev), with a DNS-TXT chunked-base64 fallback via tin.dl.well1.site / tina.dl.well1.site / ldr.dl.well1.site / win.dl.well1.site. Destinations are assembled at runtime by joining split string fragments to hide them from inspection. The fetched bytes are written to /var/tmp/.cache<rand> on POSIX or to the Windows temp directory as dotnet_diag_<rand>.exe, chmod'd 0755, and spawned detached via /bin/sh -c '<path> &' or cmd /c start /b. Cover-story comments reference a nonexistent SHA-256 integrity check and telemetry opt-out env vars (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK) that do not actually gate the dropper. A second copy of the dropper primitives (base64 decode, chmod 0755, detached /bin/sh spawn) is bundled in lib/telemetry.js (~81KB, framed as an 'Analytics SDK'), dormant but enabled by a one-line require change. Package name typosquats a Tinkoff-branded internal package.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for tinkoff-statist-browser-typed-client-cardsmobile.events.promotest (version 20.8.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging tinkoff-statist-browser-typed-client-cardsmobile.events.promotest across your stack and pipelines.
If you installed it — respond
tinkoff-statist-browser-typed-client-cardsmobile.events.promotest is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If tinkoff-statist-browser-typed-client-cardsmobile.events.promotest was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks tinkoff-statist-browser-typed-client-cardsmobile.events.promotest before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks tinkoff-statist-browser-typed-client-cardsmobile.events.promotest-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.