Which versions of claude-content-writer are malicious?

The following npm versions of claude-content-writer are flagged malicious: 2.2.0. Treat any of these as compromised.

How do I remediate claude-content-writer if I installed it?

Remove claude-content-writer from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

I already installed claude-content-writer — how do I know if it already compromised me?

If claude-content-writer 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.

Is claude-content-writer part of a known attack campaign?

Yes — claude-content-writer is associated with the IN-MAL-2026-004037 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 claude-content-writer across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for claude-content-writer (version 2.2.0).

Malicious package

claude-content-writernpm

Advisory published May 21, 2026Updated May 26, 2026

claude-content-writer is a confirmed malicious npm package (MAL-2026-4524) that executes malicious code on install (malicious version 2.2.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in claude-content-writer (npm)

MAL-2026-4524

Immediate action

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

npm uninstall claude-content-writer

What this malware does

On npm install, the package's postinstall hook runs scripts/install-dependencies.sh, which performs git clone --depth 1 https://github.com/AgriciDaniel/claude-seo.git and git clone of github.com/blader/humanizer into ~/.claude/skills with no commit pinning, then cd claude-seo && bash install.sh. The cloned repositories are personal GitHub accounts unrelated to the package publisher; whatever code their maintainers (or an attacker who takes over either account) push to HEAD will execute on every installer's machine at install time. There is no integrity verification, version pinning, or publisher-matching for the fetched code. Additionally, package.json declares the package itself as a dependency (claude-content-writer: ^2.0.1), which expands the install-time trust surface unpredictably by pulling another published version of the same package during resolution.

Malicious versions

1 flagged

2.2.0

Indicators of compromise (SHA-256)

b38e69b148dc7998c9ab02fb5b6c2a90413a88129cf7db96b1c900e9c830f719

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for claude-content-writer (version 2.2.0).
If you installed it — respond
Remove claude-content-writer from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If claude-content-writer 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. claude-content-writer on npm has been identified as a malicious package (version 2.2.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-004037

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks claude-content-writer-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.

Malware detection Runtime egress monitoring

Explore

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