tinkoff-ui-angular-addon-wysiwygnpm
tinkoff-ui-angular-addon-wysiwyg is a confirmed malicious npm package (MAL-2026-12283) that opens a backdoor for remote access (malicious version 20.7.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tinkoff-ui-angular-addon-wysiwyg (npm)
What this malware does
The package impersonates a Tinkoff UI Angular addon but ships only a stub class plus a dropper at ext.js that is loaded via index.js on require. On load, ext.js downloads a platform-specific native executable over HTTPS from runtime-reconstructed Cloudflare Workers subdomains (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS TXT-record fallback channel that reassembles chunked base64 payloads from tin.dl.well1.site and related subdomains. The fetched binary is written to a temporary path under a masquerade name (dotnet_diag<tag>.exe on Windows, hidden.cache<tag> on Unix), chmodded 0755, and spawned detached via /bin/sh -c or cmd. No hash or signature verification is performed; C2 hostnames are assembled from split string arrays (e.g. ["oob-worker.cf99-9b3.workers.d","ev"].join("")) to evade static grep. Cover-story identifiers such as analytics_state, DISABLE_TELEMETRY, and CDN-compatibility comments disguise the drop-and-execute behavior.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for tinkoff-ui-angular-addon-wysiwyg (version 20.7.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging tinkoff-ui-angular-addon-wysiwyg across your stack and pipelines.
If you installed it — respond
tinkoff-ui-angular-addon-wysiwyg 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.
Did it already run?
If tinkoff-ui-angular-addon-wysiwyg 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-ui-angular-addon-wysiwyg 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-ui-angular-addon-wysiwyg-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.