{"answers":{"affected":"1 open source package ship an affected version, including zkjson.","exploited":"There is no known exploitation of MAL-2026-4739 in the wild and no public exploit code.","fix":"Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.","what":"MAL-2026-4739 is a malicious package in zkjson, published on 26 May 2026."},"fix_prompt":"MAL-2026-4739 is a malicious package: zkjson (npm). Every version was published to cause harm.\n\nTask:\n1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.\n2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.\n3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.\n4. If the package is not used anywhere, say so and change nothing.\n\nReference: https://insights.sbomify.com/MAL-2026-4739/ (Markdown: https://insights.sbomify.com/MAL-2026-4739/index.md)","id":"MAL-2026-4739","markdown":"https://insights.sbomify.com/MAL-2026-4739/index.md","name":"MAL-2026-4739","record":{"aliases":[],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"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.\n\nThis 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.","ecosystems":["npm"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":false,"headline":"Malicious code in zkjson (npm)","id":"MAL-2026-4739","indexable":true,"kev":null,"kind":"malicious","links":{"ecosystem":"npm","product":null,"products":[],"type":null,"year":"2026"},"n_packages":1,"n_references":null,"packages":[{"ecosystem":"npm","fixed":[],"introduced":[],"last_affected":[],"package":"zkjson","purl":"pkg:npm/zkjson","source":"MAL-2026-4739"}],"products":null,"published":"2026-05-26","related":[],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"OpenSSF Malicious Packages","prefix":"MAL"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":null,"url":"https://insights.sbomify.com/MAL-2026-4739/"}