chai-spycorenpm
chai-spycore is a confirmed malicious npm package (MAL-2026-6907) that executes malicious code on install (malicious versions 1.1.0, 1.5.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-spycore (npm)
What this malware does
Package republishes the chai-spies Chai plugin source verbatim (including original author header) under the near-identical name chai-spycore. package.json declares six runtime dependencies — fast-deep-equal, eventemitter3, lodash.clonedeep, chai-guard, is-plain-object, just-extend — but none of these are require()d anywhere in lib/spy.js or index.js. The legitimate chai-spies ships with zero runtime dependencies, so the additional deps are pulled into the installer's tree on npm install chai-spycore without serving any function in the package's own code. The non-mainstream chai-guard dependency is the most suspicious of the set and is the likely vehicle for any indirect code execution against the installer. Routing to human review to assess the name-confusion claim against chai-spies and to inspect chai-guard's 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
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chai-spycore (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chai-spycore across your stack and pipelines.
If you installed it — respond
Remove chai-spycore 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 chai-spycore 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 chai-spycore 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 chai-spycore-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.