Which versions of zkjson are malicious?

The following npm versions of zkjson are flagged malicious: 0.8.5. Treat any of these as compromised.

How do I remediate zkjson if I installed it?

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

If zkjson 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 zkjson part of a known attack campaign?

Yes — zkjson is associated with the IN-MAL-2026-004810 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 zkjson 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 zkjson (version 0.8.5). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging zkjson across your stack and pipelines.

Malicious package

zkjsonnpm

Malicious code in zkjson (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-4739

Immediate action

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

npm uninstall zkjson

What this malware does

package.json declares "preinstall": "./.github/scripts/precheck", pointing to a 976 KB Linux ELF executable (sha256 36abd242ddaa27f0160c539377a0e92cf781c1695137850acc87e3892b436d36) shipped inside the tarball at .github/scripts/precheck. The binary runs automatically with the installer's privileges on every npm install. The package self-describes as a pure-JS 'Zero Knowledge Provable JSON' library whose main exports only JS classes from cjs/index.js; there is no source, build script, documentation, or stated purpose justifying a native executable. Extracted strings indicate HTTP-client primitives (HTTP/1.1, POST, GET, Host:, https://) and OAuth-related tokens, consistent with a network-active payload. There is no version pinning, no hash verification, and no reproducible build path for the binary — the published bytes are the only artifact installers receive. Shipping an opaque networked ELF as a preinstall hook in a library that advertises no native component is the canonical install-time dropper shape and gives the publisher arbitrary code execution on every installer's machine.

This package was compromised as part of the IronWorm campaign. This campaign executes a malicious binary payload during installation via a preinstall hook. The payload is a Rust-built infostealer that targets developer environments, scanning for and harvesting credentials related to cloud providers, object storage, databases, source-control, package registries, and AI developer tools. It also targets cryptocurrency wallets, specifically injecting a malicious JavaScript hook into the Exodus desktop wallet to capture passwords and recovery phrases. Furthermore, the malware exhibits worm-like behavior by stealing GitHub and NPM credentials to push malicious updates to the victim's repositories and publish trojanized packages, and it uses an eBPF-based kernel rootkit to hide its processes and network connections on Linux systems.

Malicious versions

1 flagged

0.8.5

Indicators of compromise (SHA-256)

758a19e42db66cf6ae7a08d462278b30e3a154b56613d2d95f8020de3add3816

146faaf0d97c6a533a969bc3f3f117811f9317dc865ed4ab37f1679842ddeaae

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 zkjson (version 0.8.5). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging zkjson across your stack and pipelines.
If you installed it — respond
zkjson 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 zkjson 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 zkjson 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. zkjson on npm has been identified as a malicious package (version 0.8.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-004810

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks zkjson-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