MAL-2026-5435 Malicious code in ac_semantic-ui_ts (npm)

Malicious package Published
Package
ac_semantic-ui_ts
Registry
npm

What is MAL-2026-5435?

MAL-2026-5435 is a malicious package in ac_semantic-ui_ts, published on 9 Jun 2026.

Official description

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.

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.

What should I do about MAL-2026-5435?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

Sources

Also known as GHSA-hjh8-hv66-6mwc.

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