claims-payout-offer-api-adaptersnpm
claims-payout-offer-api-adapters is a confirmed malicious npm package (MAL-2026-12633) that steals credentials and exfiltrates sensitive data (malicious version 35.2.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in claims-payout-offer-api-adapters (npm)
What this malware does
On require() of the package's main entry, index.js loads support.js which downloads a platform-specific binary from split/obfuscated Cloudflare Workers hostnames (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS-TXT base64 fallback across numbered subdomains of dl.wel1.ru. The fetched binary is written to a temp path with a deceptive name (dotnet_diag<hex>.exe /.cache_<hex>), chmod 0755 on Unix, and spawned detached via cmd.exe or /bin/sh -c with.unref(). Hostnames are reconstructed at runtime via Array.join("") of split fragments to evade static analysis. There is no version pin, hash check, or signature verification on the downloaded bytes, and the delivery hosts are not the package's publisher domain. The fetch-and-execute chain fires unconditionally on import unless specific env vars are set, so any consumer that installs and requires this package auto-runs attacker-controlled code.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for claims-payout-offer-api-adapters (version 35.2.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging claims-payout-offer-api-adapters across your stack and pipelines.
If you installed it — respond
claims-payout-offer-api-adapters is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If claims-payout-offer-api-adapters 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-payout-offer-api-adapters 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-payout-offer-api-adapters-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.