Which versions of env_express are malicious?

Every published version of env_express on npm is considered malicious. Remove the package entirely.

How do I remediate env_express if I installed it?

env_express establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

I already installed env_express — how do I know if it already compromised me?

If env_express 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.

Is env_express part of a known attack campaign?

Yes — env_express is associated with the GHSA-gw3g-c463-2jw5 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find env_express across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for env_express (all published versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging env_express across your stack and pipelines.

Malicious package

env_expressnpm

Malicious code in env_express (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-2901

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall env_express

What this malware does

env_express is a malicious npm package that when imported downloads a C2 dropper from https://jsonkeeper[.]com/b/ZK45J and executes it (similar to malware in to chai-await-test).

The package env_express was found to contain malicious code.

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

all versions

Every published version of this package is considered malicious — remove it entirely.

Indicators of compromise (SHA-256)

f84d84c7b0936e2d6323c5680ac23de0b59ea3fe1e25fa52e6bf0435cf7340ac

48199406c2296ae0d4ae9130828e2bcde05514162b7dc0951f4847aaf07827da

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for env_express (all published versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging env_express across your stack and pipelines.
If you installed it — respond
env_express establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If env_express 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 env_express 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

No. env_express on npm has been identified as a malicious package (all published versions flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-gw3g-c463-2jw5

References

Credits

Amazon Inspector · finder
indece · finder

Detect & block this

O3 blocks env_express-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring