claims-historical-claims-api-adaptersnpm
claims-historical-claims-api-adapters is a confirmed malicious npm package (MAL-2026-12624) that executes malicious code on install (malicious version 35.7.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in claims-historical-claims-api-adapters (npm)
What this malware does
index.js unconditionally requires loader.js on module load. loader.js reconstructs remote hostnames from split string fragments (e.g. ["oob-worker.cf99-9b","3.wo","rk","ers.d","ev"].join("")) to yield oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, and oob-worker.cf102-baf.workers.dev, with a DNS-TXT chunked-base64 fallback via sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. Based on process.platform, a binary is downloaded over HTTPS, written to /var/tmp or %TEMP% under a disguised name (.cache<rand> or dotnet_diag<rand>.exe), chmod'd 0755, and spawned detached via cp.spawn("/bin/sh",["-c", fp+" &"],{detached:true,stdio:"ignore"}).unref(). A parallel dropper module lib/telemetry.js, framed as an 'Analytics SDK', ships the same fetch-write-exec shape with require("child_"+"process") and fs["chmod"+"Sync"] dynamic property assembly. The obfuscation of host strings and module names, disguised filenames, and detached background execution are consistent with a canonical import-time RCE dropper.
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-historical-claims-api-adapters (version 35.7.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging claims-historical-claims-api-adapters across your stack and pipelines.
If you installed it — respond
Remove claims-historical-claims-api-adapters 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-historical-claims-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-historical-claims-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-historical-claims-api-adapters-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.