tinkoff-boxy-independent-kasko-formnpm
tinkoff-boxy-independent-kasko-form is a confirmed malicious npm package (MAL-2026-12233) that executes malicious code on install (malicious version 20.1.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tinkoff-boxy-independent-kasko-form (npm)
What this malware does
On require of the package, index.js loads bootstrap.js which reconstructs hardcoded hostnames via split-string.join obfuscation and downloads a platform-specific binary from Cloudflare Workers subdomains (oob-worker.cf101-adf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev). If HTTPS mirrors fail, resolveDns() reads a chunk count from c.<domain> TXT records and fetches base64-encoded payload chunks from N.tin.dl.well1.site TXT records, reassembling them into an executable. The payload is written to /tmp or %TEMP% under disguised filenames (.cache<hex>, dotnet_diag_<hex>.exe), chmod 0755, and spawned detached via cp.spawn("/bin/sh", ["-c", filePath + " &"]) or cmd equivalent on Windows. The package name references an unrelated 'kasko form' library, unrelated to the dropper behavior. lib/telemetry.js ships a second copy of the same drop-and-exec logic under an 'analytics SDK' cover story.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for tinkoff-boxy-independent-kasko-form (version 20.1.3). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging tinkoff-boxy-independent-kasko-form across your stack and pipelines.
If you installed it — respond
Remove tinkoff-boxy-independent-kasko-form from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If tinkoff-boxy-independent-kasko-form 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-boxy-independent-kasko-form 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-boxy-independent-kasko-form-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.