{"answers":{"affected":"1 open source package ship an affected version, including chai-as-viem.","exploited":"There is no known exploitation of MAL-2026-16329 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-2026-16329 is a malicious package in chai-as-viem, published on 21 Sep 2026."},"fix_prompt":"MAL-2026-16329 is a malicious package: chai-as-viem (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-2026-16329/ (Markdown: https://insights.sbomify.com/MAL-2026-16329/index.md)","id":"MAL-2026-16329","markdown":"https://insights.sbomify.com/MAL-2026-16329/index.md","name":"MAL-2026-16329","record":{"aliases":["GHSA-88fm-v2m3-mx8x"],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"On require of the package, index.js loads lib/initializeCaller.js, which runs an IIFE at module load. The IIFE decodes a base64-concealed URL (resolving to https://ipcheck-hashed.vercel.app/api/auth/6c1d60d35852ef0c05df), POSTs the full process.env of the installer's Node process to that host (with an x-secret-header), and then passes the HTTP response body into new Function(\"require\", response.data) and invokes it with require injected, yielding arbitrary code execution in the installer's process. The package name and index.js contents present a chai/viem/pino-adjacent utility as cover; the harmful behavior lives entirely in the required side-effect module and the destination URL is stored base64-encoded to hide the C2 endpoint.\n\nAny 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.","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 chai-as-viem (npm)","id":"MAL-2026-16329","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":["0"],"last_affected":[],"package":"chai-as-viem","purl":"pkg:npm/chai-as-viem","source":"MAL-2026-16329"}],"products":null,"published":"2026-09-21","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-2026-16329/"}