ctf-flarenpm
Malicious code in ctf-flare (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
package.json declares a postinstall script that runs node src/install.js after building a local binary. src/install.js is a 175 KB single-line payload obfuscated with a Function(...) constructor wrapper, LZString-compressed UTF-16 string tables, and per-helper rotated base85 alphabets. Once de-obfuscated, the payload resolves the strings child_process, node-fetch/fetch, -c, shell, detached, stdio, ignore, performs an outbound fetch(url, {headers:...}), reads the response body, and passes it to require('child_process').spawn('sh', ['-c', <fetched-body>], {shell, detached, stdio:'ignore'}). This fires unattended on npm install and runs attacker-controlled shell content with the installer's privileges. The multi-layer obfuscation (Function-constructor + LZString + rotated alphabets + global rebinding through aliased getters such as FTecFy['G9V6x7'] === require) exists solely to hide the fetch-and-exec from scanners and reviewers; legitimate install tooling does not need that. The shipped bin/flare binary built by make is a local CTF-style reverse-engineering challenge (ptrace anti-debug, hardcoded magic constants, XOR-decoded flag string) and is not the installer-harm vector — the dropper in src/install.js is. The CTF framing in the README does not neutralize the install-time RCE: any developer running npm install ctf-flare executes whatever shell text the remote endpoint serves at that moment.
The OpenSSF Package Analysis project identified 'ctf-flare' @ 1.0.0 (npm) as malicious.
It is considered malicious because:
- The package executes one or more commands associated with malicious behavior.
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 ctf-flare (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ctf-flare across your stack and pipelines.
If you installed it — respond
Remove ctf-flare 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 ctf-flare 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 ctf-flare 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
- OpenSSF: Package Analysis · finder
Detect & block this
O3 blocks ctf-flare-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.