ts-ecronpm
ts-ecro is a confirmed malicious npm package (MAL-2026-5647) that typosquats a legitimate package to trick installs (malicious versions 0.0.5, 0.0.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in ts-ecro (npm)
What this malware does
Package is published as 'ts-ecro' but ships a verbatim copy of big.js v7.0.1 with the original author's copyright, email, and GitHub repository URL — a typosquat/impersonation façade for the upstream big.js library. At module top-level, the entrypoint require()s a sibling attacker-controlled package and immediately invokes its from_str() method, executing arbitrary code from that dependency on every import. The CommonJS variant (big.js:606-608) loads 'websocket-slot' and calls doc.from_str().then(...).catch(...); the ESM variant (big.mjs:606-608) wraps require("parket-slot") + doc.from_str() in a try/catch that swallows errors so the import appears clean. package.json declares 'parket-slot': '^0.0.6' as a runtime dependency, ensuring the loader executes on a default install. The genuine big.js library has no such require call — the loader is appended on top of an otherwise-legitimate codebase to disguise the attack. Any project that installs and imports this package automatically runs whatever code parket-slot / websocket-slot ships, with attacker control over those packages' contents.
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
TyposquatFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for ts-ecro (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ts-ecro across your stack and pipelines.
If you installed it — respond
ts-ecro is a typosquat — you almost certainly intended a legitimately-named package. Remove ts-ecro, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If ts-ecro 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 ts-ecro 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 ts-ecro-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.