Which versions of composite-reducer are malicious?

The following npm versions of composite-reducer are flagged malicious: 1.0.2, 1.0.3, 1.0.4, 1.0.5. Treat any of these as compromised.

How do I remediate composite-reducer if I installed it?

composite-reducer is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed composite-reducer — how do I know if it already compromised me?

If composite-reducer 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 composite-reducer part of a known attack campaign?

Yes — composite-reducer is associated with the GHSA-grg7-759x-5638, RLMA-2025-06099 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 composite-reducer 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 composite-reducer (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging composite-reducer across your stack and pipelines.

Malicious package

composite-reducernpm

Malicious code in composite-reducer (npm) Remove it immediately and rotate any exposed credentials.

MAL-2025-190951

Immediate action

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

npm uninstall composite-reducer

What this malware does

The package composite-reducer was found to contain malicious code.

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.

This package was compromised by the Sha1-Hulud: The Second Coming NPM worm. The malicious payload steals tokens and credentials and publishes them to GitHub. The worm will propogate itself to NPM packages the user owns and establish persistence is a GitHub action. The package may also destroy the user's home directory.

Malicious versions

4 flagged

1.0.21.0.31.0.41.0.5

Indicators of compromise (SHA-256)

b6bf987bf2637f09fcd4a77d19b6c4f55f5c15a2e9e9d335ba7677e677cdc288

8eecfe869a6cc75f59e734412ec583d6bb95ddaab6b45c9c22526ba7b556e004

f3509f0832b284653ec2bb1521584ee0dae62629e1505cfed8dd8438fe08f2e5

170909fb1698b59f887a8efae2c4ddb60204010417283dd8f93db410facb8b9f

13e567ae66aa5491c22cd23d38834feb0bd36043c52ae7d37ab44d66a6840666

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for composite-reducer (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging composite-reducer across your stack and pipelines.
If you installed it — respond
composite-reducer is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If composite-reducer 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 composite-reducer 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. composite-reducer on npm has been identified as a malicious package (versions 1.0.2, 1.0.3, 1.0.4, 1.0.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-grg7-759x-5638RLMA-2025-06099

References

Credits

Amazon Inspector · finder
ReversingLabs · finder

Detect & block this

O3 blocks composite-reducer-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring