Popular nx packages compromised on npm

A malicious postinstall payload was injected into several @nx npm packages (multiple specified versions) that collected local secrets (wallets, SSH keys, .env, .npmrc), harvested GitHub and npm credentials, appended a shutdown command to shell profiles, and exfiltrated the data by creating public GitHub repositories (s1ngularity-repository[-X]) containing double-base64-encoded results; affected users should check for created repos, rotate all secrets, and remove the shutdown entry from shell profiles.