OpenSSF/OSV advisory MAL-2026-5435 confirms this npm version as malicious. package.json declares a postinstall hook that runs canary.js, which issues an HTTP GET to bare IP 157.230.17.236 on port 80 with query parameters including os.hostname(), the package name and version, a nonce, and a lifecycle phase. The package name `ac_semantic-ui_ts` paired with the inflated version `99.99.100` is the canonical dependency-confusion shape — designed to win resolution over an internal/private...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in ac_semantic-ui_ts (npm)
Details
package.json declares a postinstall hook that runs canary.js, which issues an HTTP GET to bare IP 157.230.17.236 on port 80 with query parameters including os.hostname(), the package name and version, a nonce, and a lifecycle phase. The package name `ac_semantic-ui_ts` paired with the inflated version `99.99.100` is the canonical dependency-confusion shape — designed to win resolution over an internal/private registry entry of the same name. Any installer who resolves this package from public npm silently transmits their host identifier to an unencrypted, hardcoded, non-publisher endpoint with no opt-in. The README self-describes as an 'authorized benign dependency-confusion canary,' but the supply-chain mechanism — install-time exfiltration of installer host metadata to a third-party IP — is identical to a malicious dependency-confusion beacon, and any installer who pulls this unintentionally has their hostname leaked.
## Source: ghsa-malware (0b851ebb2296d70685237abcc172029170d7c9e77e829c9a39d58188838e8db5) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Decision reason
OpenSSF Malicious Packages via OSV confirms ac_semantic-ui_ts@99.99.100 as malicious (MAL-2026-5435): Malicious code in ac_semantic-ui_ts (npm)