MAL-2026-13417 Malicious code in @ccfly/setup-linux-arm64 (npm)

The package ships a 6.3 MB linux/arm64 Go binary at bin/ccfly-setup. The binary embeds github.com/creack/pty (PTY spawner) and github.com/gorilla/websocket alongside internal packages github.com/ccfly/rescue/internal/{agent,setup,proto}, and contains hardcoded remote endpoints ws://ccflycc.hn, wss://…, https://cc.hn, and latest.ccfly, together with strings such as 'approveccfly-install' and '客户端已安装并配对' ('client installed and paired'). The binary dials the hardcoded ccfly server over WebSocket and bridges the connection to a locally spawned PTY, giving the remote endpoint an interactive shell on the host that runs it — a persistent remote-access channel controlled by whoever operates ccfly.hn. package.json declares os:linux, cpu:arm64, files:['bin'], and no scripts or bin map, so this sub-package alone is not auto-executed on npm install; it is a platform-optional payload intended to be resolved as an optionalDependency of a parent @ccfly/ wrapper, which then invokes bin/ccfly-setup and activates the remote-PTY channel on the installer's machine.