{"answers":{"affected":"1 open source package ship an affected version, including arjson.","exploited":"There is no known exploitation of MAL-2026-5189 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-2026-5189 is a malicious package in arjson, published on 4 Jun 2026."},"fix_prompt":"MAL-2026-5189 is a malicious package: arjson (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-2026-5189/ (Markdown: https://insights.sbomify.com/MAL-2026-5189/index.md)","id":"MAL-2026-5189","markdown":"https://insights.sbomify.com/MAL-2026-5189/index.md","name":"MAL-2026-5189","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\"`, which on `npm install` executes a 976KB UPX-packed Linux ELF binary shipped under `.github/scripts/` (a path designed to look like CI tooling). The binary has no accompanying source, is compressed with UPX (`http://upx.sf.net` banner present in the packed image) to defeat static inspection, and its embedded strings reveal capabilities far beyond anything a JSON serialization library would require: libbpf/eBPF (`LIBBPF_0.0`), kernel tracing (`PTRACE`), netlink socket-diag enumeration (`NETLINK_*_DIAG`, `INODE`), HTTP client primitives (`HTTP/1.1`, `POST`, `DELETE`), GitHub API client (`2022-11-28`), Windows path handling (`USERPROFILE`), and asymmetric crypto (Ed25519, MLKEM, RSA_PKCS1_). Any developer or CI system running `npm install arjson` on Linux will execute opaque packed native code with kernel-level introspection and HTTP-exfiltration capability. The package is advertised as a JSON library; no legitimate purpose exists for shipping a packed eBPF/HTTP-capable preinstall binary.\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 arjson (npm)","id":"MAL-2026-5189","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":"arjson","purl":"pkg:npm/arjson","source":"MAL-2026-5189"}],"products":null,"published":"2026-06-04","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-2026-5189/"}