claims-fixtures-sharednpm
claims-fixtures-shared is a confirmed malicious npm package (MAL-2026-12615) that executes malicious code on install (malicious version 35.8.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in claims-fixtures-shared (npm)
What this malware does
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for claims-fixtures-shared (version 35.8.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging claims-fixtures-shared across your stack and pipelines.
If you installed it — respond
Remove claims-fixtures-shared from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If claims-fixtures-shared was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks claims-fixtures-shared before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks claims-fixtures-shared-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.