claims-typesnpm
claims-types is a confirmed malicious npm package (MAL-2026-12645) that executes malicious code on install (malicious version 35.8.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in claims-types (npm)
What this malware does
On require('claims-types'), index.js loads./platform.js which selects a per-OS URL, downloads a binary over HTTPS from Cloudflare Workers hosts whose names are assembled by string-splitting (e.g. oob-worker.cf10{0,1,2,3}-*.workers.dev), writes it to /tmp or %TEMP% under a disguised name (.cache<hex>, dotnet_diag_<hex>.exe), chmods it to 0755, and spawns it detached via /bin/sh -c or cmd.exe with stdio ignored and unref(). A stamp file (.analytics_state) gates re-runs by TTL, providing periodic re-fetch. If HTTPS retrieval fails, _platform.js falls back to a DNS TXT covert channel: it resolves c.<domain> at *.dl.wel1.ru (sdk/ext/pkg/net.dl.wel1.ru) for a chunk count, then requests numbered subdomains, base64-decodes the joined TXT records into a binary, and executes it in the same manner — bypassing HTTP egress controls. Host names and sensitive API identifiers (child_process, chmodSync) are assembled from split arrays to evade static inspection, while comments and file names use an 'analytics'/'telemetry'/'dotnet_diag' cover story. A second dropper module at lib/telemetry.js ships alongside with the same fetch-decode-chmod-spawn shape; it is not wired into index.js in this version but is present in the tarball.
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-types (version 35.8.3). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging claims-types across your stack and pipelines.
If you installed it — respond
Remove claims-types 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-types 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-types 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-types-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.