Which versions of pewter-constantstest are malicious?

The following npm versions of pewter-constantstest are flagged malicious: 9999.0.0. Treat any of these as compromised.

How do I remediate pewter-constantstest if I installed it?

pewter-constantstest 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 pewter-constantstest — how do I know if it already compromised me?

If pewter-constantstest 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 pewter-constantstest part of a known attack campaign?

Yes — pewter-constantstest is associated with the IN-MAL-2026-004379 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 pewter-constantstest across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for pewter-constantstest (version 9999.0.0).

Malicious package

pewter-constantstestnpm

Advisory published May 23, 2026Updated May 26, 2026

pewter-constantstest is a confirmed malicious npm package (MAL-2026-4638) that steals credentials and exfiltrates sensitive data (malicious version 9999.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in pewter-constantstest (npm)

MAL-2026-4638

Immediate action

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

npm uninstall pewter-constantstest

What this malware does

On npm install, the preinstall script callback.js collects the installer's hostname, OS username, current working directory, npm registry configuration, and CI repository identifiers from a broad list of CI environment variables (GITHUB_REPOSITORY, CI_PROJECT_PATH, BUILD_REPOSITORY_NAME, BITBUCKET_REPO_FULL_NAME, TRAVIS_REPO_SLUG, DRONE_REPO, BUILDKITE_PIPELINE_SLUG, CIRCLE_PROJECT_REPONAME, JOB_NAME) and transmits them via plaintext HTTP GET to the hardcoded bare IP http://75.119.137.232:31337/depconfuse. The package has no functional surface: index.js exports an empty object, the description is the generic Shared utility helpers., the README is 48 bytes, and the version is 9999.0.0 — the canonical dependency-confusion override version designed to win resolution against an internal package of the same name. The package exists solely to fire the beacon when an organization accidentally resolves this public name in place of a private/internal package, leaking the victim's identity and internal repo names to the attacker for follow-on targeting.

Malicious versions

1 flagged

9999.0.0

Indicators of compromise (SHA-256)

050b19d8dad7c8c1a626c953493c23b375e434128f38950625f82b0fb244eabe

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for pewter-constantstest (version 9999.0.0).
If you installed it — respond
pewter-constantstest 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 pewter-constantstest 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. pewter-constantstest on npm has been identified as a malicious package (version 9999.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-004379

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks pewter-constantstest-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

Explore

All malware advisories How O3 detects malware Vulnerability database