ulid-xyznpm
Malicious code in ulid-xyz (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
ulid-xyz is a typosquat of the popular ulid library (sortable unique IDs) and is a cross-platform Remote Access Trojan delivered via a postinstall hook. The package.json postinstall superficially looks like an inline node -e guard that checks for the existence of a dist file, but it actually launches dist/node/utils.js as a detached background process, which in turn runs dist/node/payload.js -- a 467 KB bundled RAT. payload.js decodes XOR+base64-obfuscated configuration (_CFG.WS / _CFG.HTTP) to beacon to a hardcoded attacker-controlled C2 over WebSocket at ws://95.216.232.162:8010/ (with an HTTP fallback at http://95.216.232.162:8010/), establishing a WebSocket RAT channel. It installs persistence on all three major operating systems under the stem MicrosoftSystem64: on Windows under %LOCALAPPDATA%\MicrosoftSystem64; on macOS under ~/Library/Application Support/MicrosoftSystem64 plus a LaunchAgent at ~/Library/LaunchAgents/com.launchkeeper.MicrosoftSystem64.plist; and on Linux under ~/.local/share/MicrosoftSystem64. The install-time detached spawn (process management capability) and the ~8x package size spike (64 KB to 536 KB) correspond to the bundled RAT payload -- behavior a ULID library has no legitimate need for. All versions of ulid-xyz were published by the same actor (iloiyxo643 / [email protected], a disposable email address) and are considered malicious.
Malicious versions
Every published version of this package is considered malicious — remove it entirely.
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 ulid-xyz (all published versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ulid-xyz across your stack and pipelines.
If you installed it — respond
ulid-xyz 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 ulid-xyz 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 ulid-xyz 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
Credits
- SafeDep · finder
Detect & block this
O3 blocks ulid-xyz-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.