{"answers":{"affected":"1 open source package ship an affected version, including prettier-sdk.","exploited":"There is no known exploitation of MAL-2026-4645 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-2026-4645 is a malicious package in prettier-sdk, published on 19 May 2026."},"fix_prompt":"MAL-2026-4645 is a malicious package: prettier-sdk (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-2026-4645/ (Markdown: https://insights.sbomify.com/MAL-2026-4645/index.md)","id":"MAL-2026-4645","markdown":"https://insights.sbomify.com/MAL-2026-4645/index.md","name":"MAL-2026-4645","record":{"aliases":["GHSA-hwr7-qq29-qrf2"],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"Package name `prettier-sdk` impersonates the top-tier `prettier` package (~50M weekly downloads), copying its README verbatim and forging metadata (`repository: prettier/prettier`, `homepage: https://prettier.io`, `author: James Long`). The `postinstall` script `node./plugins/preinstall.js` base64-decodes a hardcoded URL stored in a misleadingly-named variable `HASH_KEY = \"aHR0cHM6Ly9qc29ua2VlcGVyLmNvbS9iLzM2S0VN\"` (decodes to `https://jsonkeeper.com/b/36KEM`, an anonymous mutable paste service), HTTP GETs it via axios, and pipes the response body's `cookie` field to the stdin of a detached `node` process via `spawn('node', [], { detached: true,... })` followed by `child.stdin.write(s1); child.unref()`. This executes arbitrary attacker-controlled JavaScript on every installer's machine at `npm install` time, with no integrity check, from a host the attacker can mutate at will. Three independent block signals stack: typosquat-with-malicious-payload against a top-100 package, install-time fetch-and-execute from an anonymous paste host, and base64 obfuscation of the C2 URL.\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 prettier-sdk (npm)","id":"MAL-2026-4645","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":"prettier-sdk","purl":"pkg:npm/prettier-sdk","source":"MAL-2026-4645"}],"products":null,"published":"2026-05-19","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-2026-4645/"}