clx-cookieparsernpm
clx-cookieparser is a confirmed malicious npm package (MAL-2026-6661) that steals credentials and exfiltrates sensitive data (malicious versions 1.4.4, 1.4.5, 1.4.6…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in clx-cookieparser (npm)
What this malware does
Package ships a verbatim copy of the Express 'cookie-parser' middleware under a different name ('clx-cookieparser') and declares a repository field 'expressjs/clx-cookieparser' that does not exist under the expressjs GitHub organization, suggesting unauthorized association with the upstream project. The shipped code (index.js requires 'cookie' and 'cookie-signature' and re-implements cookie-parser) contains no network I/O, no install/lifecycle scripts, no obfuscation, and no credential handling — there is no demonstrated installer-side harm. The concern is name/metadata confusion: a developer searching for or mistyping 'cookie-parser' could install this lookalike, and the false repository attribution amplifies the confusion. Routing to human review so a maintainer can assess intent (benign mirror vs. squat positioning) and registry action.
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 clx-cookieparser (7 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging clx-cookieparser across your stack and pipelines.
If you installed it — respond
clx-cookieparser 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 clx-cookieparser 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 clx-cookieparser 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 clx-cookieparser-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.