MAL-2026-12615 Malicious code in claims-fixtures-shared (npm)
Malicious package
Published
MAL-2026-12615 is a malicious package: claims-fixtures-shared (npm). Every version was published to cause harm.
Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.
Reference: https://insights.sbomify.com/MAL-2026-12615/ (Markdown: https://insights.sbomify.com/MAL-2026-12615/index.md)
- Package
- claims-fixtures-shared
- Registry
- npm
What is MAL-2026-12615?
MAL-2026-12615 is a malicious package in claims-fixtures-shared, published on 5 Aug 2026.
Official description
On require('claims-fixtures-shared'), index.js loads helpers.js which immediately calls init(). init() reconstructs four Cloudflare Workers hostnames (oob-worker.cf101-adf.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev) and a set of DNS TXT-record resolvers (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) via runtime array.join("") to evade static string scanners, then downloads a per-platform binary via https.get, writes it to /tmp or %TEMP% under a masquerading filename (.cache<rnd> on unix, dotnet_diag_<rnd>.exe on Windows), fs.chmodSync 0o755, and spawns it detached via /bin/sh -c or cmd. No signature or hash verification is performed despite a '// SHA-256 integrity check' cover-story comment; a DNS TXT-record fallback channel and a.analytics_state lock file for rerun throttling are present. The package's stated purpose is a trivial fixtures helper, unrelated to any native binary. Env-var opt-outs (DISABLE_TELEMETRY, DO_NOT_TRACK) frame the code as telemetry while it stages and executes an arbitrary attacker-controlled payload.
What should I do about MAL-2026-12615?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.