The @ccfly/setup-linux-arm64 npm package (version 0.1.0) includes a large Go binary that embeds PTY spawning and WebSocket libraries. It connects to hardcoded remote servers (e.g., ccflycc.hn) over WebSocket and bridges this connection to a locally spawned PTY, effectively providing remote interactive shell access to the attacker. The binary contains strings indicating client installation and pairing, suggesting a persistent remote-access trojan functionality. The package is platform-optional and not automatically executed on npm install, implying it is intended to be triggered by a parent package that uses it as an optional dependency. This behavior constitutes a malicious package designed to compromise Linux ARM64 systems where it is installed and executed.

If executed, this package grants remote attackers persistent interactive shell access on the affected Linux ARM64 host, enabling full control over the system. This can lead to unauthorized data access, system manipulation, and further compromise. The package itself is not auto-executed on install, reducing risk unless invoked by a parent package or manually executed. No known exploits in the wild have been reported yet.

No official patch or remediation guidance is currently available. Users should avoid installing or executing the @ccfly/setup-linux-arm64 package and any parent @ccfly/* packages that may invoke it. Audit dependency trees for this package and remove it if found. Monitor for any updates from the package maintainers or npm advisories for remediation. Since the package is not auto-executed on install, preventing execution of the binary mitigates the threat.