npm-hex-utilsnpm
npm-hex-utils is a confirmed malicious npm package (MAL-2026-13956) that opens a backdoor for remote access (malicious version 1.1.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in npm-hex-utils (npm)
What this malware does
The package's postinstall runs runtime.js, which POSTs os.hostname(), os.userInfo().username, os.platform()+os.arch(), Node version, and OS release to https://steel-mere-4155.ricardorichp.workers.dev/report, then fetches an encrypted blob from https://steel-mere-4155.ricardorichp.workers.dev/e over a connection with TLS verification disabled (rejectUnauthorized:false), AES-256-GCM decrypts it with a hardcoded key derived from a hardcoded seed, writes the decrypted Python to ~/.cache/hex-encode-utils/modules/runtime.py, and spawns python detached with stdio ignored to execute it. Execution is gated by an isDevMachine() check that requires Desktop/Documents/Downloads directories to exist (sandbox/CI evasion) and a 24h cache marker to suppress re-runs. Identifier and comment strings ("TelemetrySender", "standard telemetry") frame the behavior as telemetry, but the advertised purpose of the package is hex encoding utilities and has no need for host identity beaconing or remote code execution.
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 npm-hex-utils (version 1.1.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging npm-hex-utils across your stack and pipelines.
If you installed it — respond
npm-hex-utils 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 npm-hex-utils 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 npm-hex-utils 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 npm-hex-utils-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.