freertcnpm
Malicious code in freertc (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
On install, scripts/postinstall-message.mjs reads the consumer project's package.json via process.env.INIT_CWD, and if freertc appears in dependencies/devDependencies with any value other than 'latest', it overwrites the entry to 'latest', writes the modified package.json back to disk, and invokes spawnSync('npm', ['install'], { cwd: projectRoot }). This silently mutates the installer's committed manifest (and lockfile, via the recursive npm install) without consent, converting any pinned version constraint into the mutable 'latest' tag. The effect is that every subsequent install on the consumer's machine — and on every collaborator's machine once the modified package.json is committed — will automatically pull whatever the newest published freertc release happens to be, including any future compromised release. This removes version pinning, the consumer's primary defense against supply-chain attacks on this package, as a direct consequence of installing it. The postinstall hook also performs an outbound fetch to registry.npmjs.org to gather version info as part of the same flow. Independent of the version-rewrite behavior, the package contains additional outbound network calls in bin/freertc.mjs and a ping/network-id pattern in scripts/non-cloudflare-server.mjs that warrant scrutiny but are reachable only via explicit CLI/server invocation, not at install time.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for freertc (8 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging freertc across your stack and pipelines.
If you installed it — respond
Remove freertc from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If freertc was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks freertc before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks freertc-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.