On npm install, postinstall.js executes a shell pipeline that collects the output of id, os.hostname(), the full process environment (env | sort), the contents of /app/.npmrc, /usr/etc/npmrc, and /root/.npmrc, recursive listings and greps under /app (searching for HTB{...}, secrets, and flag files), and /proc/*/cmdline data. The collected blob is base64-encoded and PUT in two halves over plain HTTP to http://154.57.164.71:30782/api/modules/ECT-* (the destination is hardcoded at postinstall.js line 6 as const TARGET = "http://154.57.164.71:30782";). Execution is gated by an isChallengeWorker() check that requires cwd under /app/node_modules, a 12-hex-character hostname (Docker container ID shape), the presence of /app/Cargo.toml or /app/package.json, and explicitly suppresses the payload when the active npm registry is a Chinese mirror (npmmirror, taobao, cnpm, huawei, tencent, ustc) — environment fingerprinting designed to evade researcher and CI sandboxes while firing on the intended victim. Reading and exfiltrating .npmrc exposes //registry.npmjs.org/:_authToken=... tokens, enabling the attacker to publish malicious versions under the installer's npm identity.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.