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.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
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.