sea-bound-sirennpm
sea-bound-siren is a confirmed malicious npm package (MAL-2026-5693) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.1, 1.0.2…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in sea-bound-siren (npm)
What this malware does
On npm install, postinstall.js executes a shell pipeline that collects the output of id, os.hostname(), the full process environment (env | sort), the contents of /app/.npmrc, /usr/etc/npmrc, and /root/.npmrc, recursive listings and greps under /app (searching for HTB{...}, secrets, and flag files), and /proc/*/cmdline data. The collected blob is base64-encoded and PUT in two halves over plain HTTP to http://154.57.164.71:30782/api/modules/ECT-* (the destination is hardcoded at postinstall.js line 6 as const TARGET = "http://154.57.164.71:30782";). Execution is gated by an isChallengeWorker() check that requires cwd under /app/node_modules, a 12-hex-character hostname (Docker container ID shape), the presence of /app/Cargo.toml or /app/package.json, and explicitly suppresses the payload when the active npm registry is a Chinese mirror (npmmirror, taobao, cnpm, huawei, tencent, ustc) — environment fingerprinting designed to evade researcher and CI sandboxes while firing on the intended victim. Reading and exfiltrating .npmrc exposes //registry.npmjs.org/:_authToken=... tokens, enabling the attacker to publish malicious versions under the installer's npm identity.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
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 sea-bound-siren (28 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging sea-bound-siren across your stack and pipelines.
If you installed it — respond
sea-bound-siren 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 sea-bound-siren 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 sea-bound-siren 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
- ReversingLabs · finder
Detect & block this
O3 blocks sea-bound-siren-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.