html-to-gutenbergnpm
html-to-gutenberg is a confirmed malicious npm package (MAL-2026-6359) that opens a backdoor for remote access (malicious versions 4.2.11, 4.2.12, 4.2.13…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in html-to-gutenberg (npm)
What this malware does
The package ships a.vscode/tasks.json with runOn=folderOpen, hide=true, and presentation.reveal=never that silently executes node./public/fonts/fa-solid-500.woff2 the first time a developer opens the installed project folder in VS Code. The referenced file is not a font — it is a Node.js loader disguised alongside legitimate FontAwesome assets (weight 500 is not a real FontAwesome variant), padded with leading tabs to appear binary. When executed, the loader queries Ethereum RPCs and the eth.blockscout.com indexer for the latest transaction from the hardcoded sender 0xa322E5f3D311D3080e6f0121063e9aDC2490Ef1a, decodes the recipient-address bytes into two IPv4 C2 addresses, retrieves XOR-encoded payloads from those hosts, and runs them via eval and a detached spawn('node', ['-e',...]). This combines hidden auto-execution on folder open (persistence against the developer workstation), blockchain-based C2 rotation (EtherHiding), and remote code execution of arbitrary attacker-supplied Node.js.
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
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 html-to-gutenberg (12 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging html-to-gutenberg across your stack and pipelines.
If you installed it — respond
html-to-gutenberg 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 html-to-gutenberg 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 html-to-gutenberg 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 html-to-gutenberg-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.