babel-polyfill-plugin-corejs2npm
babel-polyfill-plugin-corejs2 is a confirmed malicious npm package (MAL-2026-14426) that executes malicious code on install (malicious version 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in babel-polyfill-plugin-corejs2 (npm)
What this malware does
The package advertises itself as a Babel core-js 2 polyfill plugin, but the shipped lib/index.js contains unrelated web3-core-subscriptions boilerplate followed by a Function() invocation whose body is ~110KB of obfuscated JavaScript (random identifiers, numeric offset arrays, TEA-like mixing routine, unicode-escape string literals). The Function() call executes whenever a consumer require()s the package, running the opaque payload at import time. The declared purpose does not match the shipped code, and the obfuscation is confined to the appended payload rather than being a general minification artifact.
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 babel-polyfill-plugin-corejs2 (version 1.0.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging babel-polyfill-plugin-corejs2 across your stack and pipelines.
If you installed it — respond
Remove babel-polyfill-plugin-corejs2 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 babel-polyfill-plugin-corejs2 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 babel-polyfill-plugin-corejs2 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 babel-polyfill-plugin-corejs2-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.