Which versions of expreeeess are malicious?

The following npm versions of expreeeess are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate expreeeess if I installed it?

Remove expreeeess 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.

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

If expreeeess was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

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

Search your lockfiles and build artifacts for expreeeess (version 1.0.0).

Malicious package

expreeeessnpm

Advisory published Apr 2, 2026Updated Apr 7, 2026

expreeeess is a confirmed malicious npm package (MAL-2026-2442) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in expreeeess (npm)

MAL-2026-2442

Immediate action

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

npm uninstall expreeeess

What this malware does

The package expreeeess was found to contain malicious code.

The OpenSSF Package Analysis project identified 'expreeeess' @ 1.0.0 (npm) as malicious.

It is considered malicious because:

The package executes one or more commands associated with malicious behavior.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

37091885c35c88368c40401469c6f665a6953fedfa94d705b9c96847708f9c53

f655863438463b445574f12a5195c9635704e2158556ae437ee3a71c2e083d6b

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for expreeeess (version 1.0.0).
If you installed it — respond
Remove expreeeess 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 expreeeess was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. expreeeess on npm has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Credits

Amazon Inspector · finder
OpenSSF: Package Analysis · finder

Detect & block this

O3 blocks expreeeess-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.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database