MAL-2026-5833 Malicious code in yunxin-overmind-comment (npm)

On npm install, the package's scripts.postinstall runs src/_postinstall.js, which spawns a detached Node child that collects the installer's hostname, username, platform/arch, cwd, Node version, npm registry, all non-internal IPv4 addresses, and the keys of environment variables matching /NPM|NODE|CI|JENKINS|GIT|BUILD|RUNNER|DOCKER|KUBE|REGISTRY/. The collected data is HTTPS-POSTed to a hardcoded DingTalk bot webhook (https://oapi.dingtalk.com/robot/send?access_token=4e5cb67f...df393). Before sending, the script checks the username and hostname against an analyst/sandbox keyword list (sandbox, malware, analyst, cuckoo, analysis, sample) and silently no-ops if any match — explicit anti-analysis evasion. The combination of automatic install-time execution, host/network reconnaissance scoped to CI/build runners, hardcoded attacker-controlled callback, and sandbox-evasion gating is the canonical dependency-confusion beacon shape. Installing this package leaks internal hostnames, IP topology, and CI/build environment fingerprints to the operator of the DingTalk webhook, enabling targeted follow-on attacks against the installer's internal infrastructure.