MAL-2026-11548 Malicious code in streak-math-abz (npm)

The package advertises itself as a JavaScript day-math helper but its ESM main entry (dist/index.mjs) unconditionally spawns a bundled Linux x86_64 ELF (dist/math-core.bin) via child_process.spawn at import time, disguised by 'CORE ENGINE INITIALIZATION' comments and a fake calibration loop wrapped in an empty catch. The ELF is a remote-access implant with a hardcoded C2 at 217.60.77.63: it exposes a /redshell command surface with SOCKS5 proxy, TCP port forwarding, and shell/binary dispatch; it drops and executes attacker-supplied ELF/shellcode payloads staged under /tmp/.elf_XXXXXX via curl to http://217.60.77.63/Others/ and /SC/; it exfiltrates arbitrary files and credentials (/ssh_keys, /creds, /dbfind, /download, /dataextract) by POSTing chunked BIGEXTRACT_START/FILE/END frames to http://217.60.77.63/api/extract-receive; and its /persist command installs a systemd user service at ~/.config/systemd/user/svc-update.service with ExecStart=/proc/self/exe and Restart=always, enabled via systemctl –user, for reboot-persistent execution. The binary performs no math and has no build/source correspondence in the package.