Findings

MAL-2026-17765

Malicious code in @s4yhiitestpoc/r3-https (npm)

Published Oct 11, 2026 · updated Oct 13, 2026

Dependency-confusion proof-of-concept package. A postinstall script runs automatically on installation and sends host and user identifiers (hostname, username, home directory, network interface addresses, platform details and npm configuration) to collector.oob.s4yhii.com, with a secondary DNS lookup under oob.s4yhii.com. It also performs a reverse DNS lookup of the host's own address and records the name and path of the project that installed it. The script states it is bug-bounty research and does not read secrets or file contents. Any machine that installed this package disclosed the listed host information to a third party. --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (b2638f8970897121676d5dc3ed7c002ab9d9ccc3e400283e165297a95e3c1423) On npm install, postinstall.js automatically collects host identity (hostname, username, uid/gid, homedir, platform, release), enumerates network interfaces (addresses, MACs, CIDRs), reads DNS servers and internal reverse-DNS names, captures npm/CI environment markers and container/runtime indicators, and walks up to eight parent directories to locate the consuming project's package.json and extract its name, version, declaring dependency field, and declared version range. The collected data is POSTed over HTTPS to the hardcoded endpoint collector.oob.s4yhii.com at path /_npm-poc/beacon, and a parallel DNS lookup to a labeled subdomain under *.oob.s4yhii.com is issued as an out-of-band beacon. The consumer manifest harvesting discloses the installer's private project identity and internal package naming to a third-party host and is the characteristic reconnaissance signal of a dependency-confusion targeting pipeline. The endpoint is not caller-configurable and there is no opt-out. ## Source: ghsa-malware (ff183ad61b543f94eaae7b4408fed43c924470b6a672090d0500b4836ff36bba) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys store

Timeline

Detection, updates, and resolution for this record.

  1. Oct 11, 2026 · Catalog

    Detected

    Dependency-confusion proof-of-concept package. A postinstall script runs automatically on installation and sends host and user identifiers (hostname, username, home directory, network interface addresses, platform details and npm configuration) to collector.oob.s4yhii.com, with a secondary DNS lookup under oob.s4yhii.com. It also performs a reverse DNS lookup of the host's own address and records

  2. Oct 13, 2026 · Catalog

    Updated

    Dependency-confusion proof-of-concept package. A postinstall script runs automatically on installation and sends host and user identifiers (hostname, username, home directory, network interface addresses, platform details and npm configuration) to collector.oob.s4yhii.com, with a secondary DNS lookup under oob.s4yhii.com. It also performs a reverse DNS lookup of the host's own address and records

Affected

  • npm @s4yhiitestpoc/r3-https1.0.0, 0.0.0-stage

Sources

References