chalk-plus-jsnpm
chalk-plus-js is a confirmed malicious npm package (MAL-2026-5709) that opens a backdoor for remote access (malicious version 7.0.4). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chalk-plus-js (npm)
What this malware does
Package is published under a name riding the popular chalk color-output library but its source tree, README, main entry (lib/nodemailer.js), and lib paths (smtp-connection, mailer, ses-transport, smtp-pool, dkim, mime-funcs) are a verbatim clone of nodemailer. The package.json description is an unrelated React Training copyright string and the homepage points at a lookalike domain (chalk-plus-js.com). On install, the postinstall hook node lib/utils/index.js spawns lib/utils/smtp-connection/index.js as a detached child with stdio fully silenced (spawn(process.execPath, [filePath], { detached: true, stdio: ['ignore','ignore','ignore'] }); child.unref()), so the dropper survives npm install exit with no console output. The target file is heavily obfuscated using a custom-alphabet string array and per-block decoders inside try/catch wrappers; decoded values are fed to require(...), spawn(...), and the argument pattern ['-e', <decoded>] with shell: true — i.e. it executes attacker-controlled code through a shell at install time. The payload requires axios, fs, path, child_process, and the package's runtime dependency footprint (axios, socket.io-client, sqlite3, request) is consistent with HTTP/websocket C2 plus local persistence — none of which a nodemailer clone needs. Any developer who mistypes or trusts the name chalk-plus-js executes attacker code with their own privileges on npm install.
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 chalk-plus-js (version 7.0.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chalk-plus-js across your stack and pipelines.
If you installed it — respond
chalk-plus-js 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 chalk-plus-js 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 chalk-plus-js 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 chalk-plus-js-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.