@s4yhiitestpoc/r2-https-b

Details

**Severity:** Critical

**Affected versions:** `= 1.0.0`

## Source: amazon-inspector (e89449bafb4f816bd8605f45cedf0fec8ec0cff9088007a7a38aaea0a9db91ec)
On npm install, postinstall.js automatically collects installer-side identifying data — hostname, username, home directory, non-internal network interface addresses, DNS servers, current working directory, install directory, and the value of npm_config_registry (which discloses the installer's internal/private npm registry URL) — and POSTs it as JSON over HTTPS to the hardcoded author endpoint collector.oob.s4yhii.com at path /_npm-poc/beacon. In parallel, the script performs a DNS lookup against a unique per-run subdomain under oob.s4yhii.com (dns.lookup of <label>.db03o8lag74hsugsg2j091t8mfcf437h3.oob.s4yhii.com), providing an out-of-band DNS confirmation channel that works even when outbound HTTPS is blocked. The dual-channel beacon, the capture of internal registry configuration, and the fully automated install-time trigger match the fingerprint of a dependency-confusion probe. The package's self-description as a proof-of-concept does not change the behavior: installer-side host and internal-infrastructure data leaves the host to an attacker-controlled destination without opt-in.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/e0a59209e17651aab243eb71401d9ac174bf2406/osv/malicious/npm/@s4yhiitestpoc/r2-https-b/MAL-2026-17808.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/e0a59209e17651aab243eb71401d9ac174bf2406/osv/malicious/npm/@s4yhiitestpoc/r2-https-b/MAL-2026-17808.json
- https://www.npmjs.com/package/@s4yhiitestpoc/r2-https-b/v/1.0.0
- https://github.com/advisories/GHSA-whjq-6xm5-ggvh

Compromised versions (1)

• = 1.0.0

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