tt-help-cli-yclnpm
tt-help-cli-ycl is a confirmed malicious npm package (MAL-2026-12488) that opens a backdoor for remote access (malicious versions 1.4.59, 1.4.60, 1.4.61). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tt-help-cli-ycl (npm)
What this malware does
The package's watchdog subcommand runs a long-lived agent that POSTs a heartbeat to a configurable remote server (default advertised as http://117.71.53.99:17301) and executes commands returned by that server. _buildHeartbeatBody collects hostname, non-loopback LAN IP, OS platform/release/arch, CPU count, memory, uptime, load average, node version, the running child-process table, and the contents of ~/.tt-help.json (server, proxy, browser path, userId), then sends them to ${serverUrl}/api/watchdog/heartbeat. The response commands array is passed unchanged to spawn('sh', ['-c', cmd]) (or cmd /c on Windows) through ProcessManager.startCommand, giving the remote server arbitrary shell execution on the host running the agent. Independently, startUpgradeChecker polls the npm registry every 10 minutes and, on any version bump, runs npm install -g tt-help-cli-ycl@latest via child_process.exec, so any future publish to the latest dist-tag is installed unattended on every running agent. The default C2 host is a bare IPv4 address on a non-standard port with no TLS.
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 tt-help-cli-ycl (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging tt-help-cli-ycl across your stack and pipelines.
If you installed it — respond
tt-help-cli-ycl 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 tt-help-cli-ycl 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 tt-help-cli-ycl 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 tt-help-cli-ycl-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.