Which versions of simplejsonform are malicious?

The following npm versions of simplejsonform are flagged malicious: 1.0.1. Treat any of these as compromised.

How do I remediate simplejsonform if I installed it?

simplejsonform 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 simplejsonform — how do I know if it already compromised me?

If simplejsonform 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 simplejsonform part of a known attack campaign?

Yes — simplejsonform is associated with the GHSA-mwfw-83jq-9c9v 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 simplejsonform across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for simplejsonform (version 1.0.1).

Malicious package

simplejsonformnpm

Advisory published Nov 24, 2025Updated Dec 1, 2025

simplejsonform is a confirmed malicious npm package (MAL-2025-191426) that steals credentials and exfiltrates sensitive data (malicious version 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in simplejsonform (npm)

MAL-2025-191426

Immediate action

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

npm uninstall simplejsonform

What this malware does

The package simplejsonform 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

1 flagged

1.0.1

Indicators of compromise (SHA-256)

b9b5d05b3d6f523408693f8ad0f958693c6fea23143ce98c72169eb2f1fb6614

fd81fbb7b9cb8cfc5e4444da9cd2d18ed54ec4b7bb741f0ad95a56ce29a5edd0

d512e223b9a2375fd46539f1b0434e092f755c299f20b1d054c538228d266436

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for simplejsonform (version 1.0.1).
If you installed it — respond
simplejsonform 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 simplejsonform 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. simplejsonform on npm has been identified as a malicious package (version 1.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-mwfw-83jq-9c9v

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks simplejsonform-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