ulid-xyznpm
ulid-xyz is a confirmed malicious npm package (MAL-2026-6672) that steals credentials and exfiltrates sensitive data (malicious versions 2.12.1, 2.12.2, 2.12.3…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in ulid-xyz (npm)
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.
Package publishes as 'ulid-xyz' — a name edit away from the established 'ulidx' / 'ulid' libraries — and its README instructs users to npm install index-ulid and import { ulid } from "index-ulid", pointing at a second confusable name maintained by the same author. The declared homepage links to the canonical ulid repository (github.com/ulid/javascript), reinforcing the impersonation. package.json declares scripts.postinstall that runs node dist/node/utils.js after a required-files guard, but dist/node/utils.js is absent from this tarball — only dist/node/index.cjs and dist/node/index.js ship. As published, the guard throws and the postinstall is inert, so no malicious code executes on install in this version. The wired-but-missing lifecycle target combined with the confusable name and a bloated runtime dependency list (pino, ws, zod, esbuild, tsup, ts-node, typescript, @types/node, @types/ws, and a meta postinstall package — none required for ULID generation, where the legitimate ulidx ships zero runtime deps) is consistent with a dormant-dropper staging pattern: ship a benign tarball under a confusable name, then publish a future version that fills in the postinstall target. No exfiltration, no install-time RCE, and no silent-relay are present in the current code, so a public block would overclaim the present-version harm. Routing to human review for confusion-risk assessment and so a reviewer can monitor future versions of this name.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for ulid-xyz (9 malicious 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 is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
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
Campaign
References
Credits
- Amazon Inspector · finder
- 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 credential exfiltration and severs the channel.