node-procmetrics @1.0.9

Summary

install.js executes automatically via the package.json postinstall hook. It XOR-decodes (key 0x5A) a hardcoded npm registry auth token and writes it into the installer's global npm config at //registry.npmjs.org/:_authToken, replacing the installer's own npm authentication with an attacker-controlled identity. It then polls registry.npmjs.org for this package's dist-tags, base64-decodes the 'cmd' field, and executes the resulting string via spawnSync('bash', ['-c', cmd],...) in an infinite loop, giving the publisher arbitrary shell execution on any machine that installs the package. The output and exit code of each executed command are base64-encoded, placed into a synthesized package.json description field under /tmp/pm-pkg, and pushed back to the public npm registry via 'npm publish --access public' using the hijacked token, using the registry itself as the exfiltration channel. For persistence, install.js copies itself to /tmp/.pm-agent.js and spawns a detached, unref'd Node process pointing at that file, so the polling loop survives past the npm install invocation. The combination of covert channel via dist-tags, XOR-obfuscated embedded credential, credential replacement in the installer's npm config, and detached persistent process is unambiguous backdoor behavior at install time.

Source: amazon-inspector (e41a88d3fab17af2429cc051cce026d47622123ce4005d3fbdda844dfca2783a)