OSV advisory

osv.dev • October 15, 2026

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 | 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 33 minutes by the npm account 'dirtyblanket' (maintainer email s7dwzxru4z@ooynib.com ), 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.

-= Per source details. Do not edit below this line.=-

Source: amazon-inspector (a84bd81adecaf93be6fe963765bf1686f6b6bcefac1b8a6124bc2841053fd265)

[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 | 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.

Amazon Inspector - FINDER [email protected]

Amazon Inspector - FINDER

[email protected]

InvisiRisk, Inc. - FINDER mailto:research@invisirisk.com

InvisiRisk, Inc. - FINDER

mailto:research@invisirisk.com

Pranesh, InvisiRisk - FINDER

SafeDep - FINDER

npm / express-javascript