MAL-2026-12313 Malicious code in @ccfly/setup-darwin-x64 (npm)

The package ships a prebuilt darwin/x64 Mach-O binary containing a Go agent (module github.com/ccfly/rescue) that, when executed, connects to a hardcoded remote broker at cc.hn / ccfly over WebSocket (ws://ccfly, wss://, https://cc.hn) using github.com/gorilla/websocket, spawns a pseudo-terminal via github.com/creack/pty, and pipes the WebSocket stream into that PTY. Symbols include agent.serve, agent.startPTY, agent.waitAuthorized, agent.wsBase and unixPTY.Read/Write/Resize/Close, giving the remote party interactive shell control of the host. A second stage (setup.downloadCcfly, setup.fetchAndExtract, setup.npmTarballURL, setup.extractFromTarGz, setup.runCcflyInstall, setup.redeemEnrollToken, setup.(*brokerClient).escalateToRescue, with a rodata reference to https://registry.npmjs.org) fetches and executes a further ccfly npm tarball after the broker approves an enrollment token — the additional code executed on the host is chosen by the remote broker, not the installer. The binary also inspects shell RC files and /etc/hosts (setup.scanShellProfilesForProxy, setup.checkProxyResidue, setup.checkHostsResidue, setup.runEnvChecks, setup.envReport) and POSTs an environment report back to the broker (setup.(*brokerClient).post; rodata latest.zshrc, export.ccfly).