NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
Malicious package

tinkoff-fb-rf-add-applicationnpm

Advisory published Updated

tinkoff-fb-rf-add-application is a confirmed malicious npm package (MAL-2026-12242) that opens a backdoor for remote access (malicious version 20.3.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in tinkoff-fb-rf-add-application (npm)

MAL-2026-12242
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
npm uninstall tinkoff-fb-rf-add-application

What this malware does

The package's main entry loads bootstrap.js on require(), which downloads a platform-specific executable from string-fragment-obfuscated Cloudflare-workers mirrors (assembled at runtime via array-join, e.g. oob-worker.cf*.workers.dev) with a DNS-TXT chunked base64 fallback under *.dl.well1.site (tin/tina/ldr/win subdomains). The fetched bytes are written to /tmp or %TEMP% under a disguised filename impersonating system binaries (dotnet_diag<tag>.exe on Windows,.cache_<tag> on Unix), chmod 0755, and spawned detached via /bin/sh -c or cmd.exe /c start /b. A lock file.analytics_state and telemetry-shaped env-var opt-outs provide a cover story. The C2 hostnames are constructed from split string fragments to evade static analysis.

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.

Malicious versions

1 flagged
20.3.5

Indicators of compromise (SHA-256)

788686e9aacdc59ec40f42563a7d9ba5020c75d6c724c8bf59623213b51df780
dded5cf8e0ac224ea75063c3dffc5faf0241f5648de3957efce29d011edc5735

Detection & response playbook

Backdoor / remote access
  1. Find it

    Search your lockfiles and build artifacts for tinkoff-fb-rf-add-application (version 20.3.5).

  2. If you installed it — respond

    tinkoff-fb-rf-add-application establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

  3. Did it already run?

    If tinkoff-fb-rf-add-application was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. tinkoff-fb-rf-add-application on npm has been identified as a malicious package (version 20.3.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-014506GHSA-pvc7-jp4m-6758

References

Credits

  • Amazon Inspector · finder

Detect & block this

O3 blocks tinkoff-fb-rf-add-application-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Explore

tinkoff-fb-rf-add-application (npm) malicious package — MAL-2026-12242 | O3 Security