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Malicious package

@markvivanco/app-version-checkernpm

Advisory published Updated

@markvivanco/app-version-checker is a confirmed malicious npm package (MAL-2025-190818) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.1, 1.0.2). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in @markvivanco/app-version-checker (npm)

MAL-2025-190818
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
npm uninstall @markvivanco/app-version-checker

What this malware does

The package @markvivanco/app-version-checker 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

2 flagged
1.0.11.0.2

Indicators of compromise (SHA-256)

9d018f3394c86414d471f91661f94f44f693cbbe7513a4cb1591bbe5d59e441a
eb3390637a7e3c1122d5f1f2417189358dec13936938bd997c1bf5949c1bb8dc
6a254647592258fb51e577a97fbef98be100c99ffb96cd120e8e5ac3f5e81159
5b9f8919301b2a5124e3dd411bc2dfaaf6cc1f80bf3a12fc838e9c9f5c5e1979

Detection & response playbook

Credential / info stealer

  1. Find it

    Search your lockfiles and build artifacts for @markvivanco/app-version-checker (2 malicious versions).

  2. If you installed it — respond

    @markvivanco/app-version-checker 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.

  3. Did it already run?

    If @markvivanco/app-version-checker 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. @markvivanco/app-version-checker on npm has been identified as a malicious package (versions 1.0.1, 1.0.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-h8fg-29cr-mrj7

References

Credits

  • Amazon Inspector · finder

Detect & block this

O3 blocks @markvivanco/app-version-checker-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
@markvivanco/app-version-checker (npm) malicious package — MAL-2025-190818 | O3 Security