Which versions of chalk-util are malicious?

The following npm versions of chalk-util are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate chalk-util if I installed it?

chalk-util 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.

I already installed chalk-util — how do I know if it already compromised me?

If chalk-util 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.

Is chalk-util part of a known attack campaign?

Yes — chalk-util is associated with the IN-MAL-2026-018250 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find chalk-util across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chalk-util (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chalk-util across your stack and pipelines.

Malicious package

chalk-utilnpm

chalk-util is a confirmed malicious npm package (MAL-2026-14168) that opens a backdoor for remote access (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in chalk-util (npm)

MAL-2026-14168

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall chalk-util

What this malware does

[email protected] is a typosquat of chalk whose index.js exports an empty object; the package's only functional code is scripts/postinstall.js. On npm install, postinstall XOR-decodes an obfuscated URL (key 'stf2026') pointing to an https://github.com/... asset, downloads it to %TEMP%\main.exe on Windows (and via a decoded PowerShell bridge command on WSL-detected Linux, identified through /proc/version), and spawns it detached with a hidden window. The same postinstall reconstructs the bare IP 193.70.34.101 via ['193','70','34','101'].join('.') and POSTs a JSON body containing the resolved platform label to http://193.70.34.101:20099/vote over plain HTTP as an install beacon. Four separate byte-array constants (ADDON_ENC, BRIDGE_LAUNCHER_ENC, BRIDGE_SCRIPT_PRE_ENC, BRIDGE_SCRIPT_POST_ENC) are XOR-decoded at runtime to hide the fetch URL and the shell command passed to exec(). The auto-execute-on-default-install gate is satisfied via the postinstall lifecycle hook; the fetched binary contents are attacker-controlled and unverified.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

4a61959df09375862d2802f22d92ed1a26066bf2ddc2618b76f89666567a91f4

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chalk-util (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chalk-util across your stack and pipelines.
If you installed it — respond
chalk-util 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-util 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-util 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

No. chalk-util on npm has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-018250

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks chalk-util-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring

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