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🛡️ MAL-2026-4739 — zkjson

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Malicious code in zkjson (npm)

Source: amazon-inspector

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.

Source: google-open-source-security

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.

Affected software

MAL-2026-4739 is recorded against 1 package.

  • zkjson

Timeline and source

Published on 26 May 2026 and last revised on 4 June 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

www.npmjs.com (Package)
www.ox.security (Article)
research.jfrog.com (Article)

Details

Severity Unknown
CVSS Score N/A
CVSS Vector N/A
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-05-26
Updated 2026-08-20
Modified 2026-06-04
Fix URL N/A

Affected Packages

Software From version Fixed in
zkjson

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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