fhirproxy-utilsnpm
Malicious code in fhirproxy-utils (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
On npm install (via the prepare lifecycle hook and many other lifecycle aliases) and on require(), index.js performs broad reconnaissance and exfiltration of the installer's environment. It collects hostname, username, architecture, working-directory tree, network interfaces, /etc/resolv.conf, process list,.git/HEAD, UID/GID, project package.json metadata, ~/.npmrc registry/scope configuration, the developer's git identity (via git config --global user.email), CI/CD environment variables (GITHUB_, GITLAB_, AWS_, CIRCLE_, etc.), and the presence of ~/.ssh, ~/.aws, ~/.kube. When running on a cloud instance it queries the IMDS endpoint at 169.254.169.254 (stored as the decimal-encoded host 2852039166), obtains an IMDSv2 token, fetches the IAM role and temporary STS credentials, and includes the first 40 characters of the access token in the payload; equivalent paths exist for Azure and GCP metadata. It also performs DNS reconnaissance against internal-only hostnames (kubernetes.default.svc.cluster.local, vault.internal, consul.service.consul, gitlab.local, jenkins.local, redis.internal, etc.) to map the victim's internal network. Collected data is base64-encoded, fragmented, and exfiltrated via chunked HTTPS GET requests to momo-rest.lapxa354.workers.dev (a Cloudflare Workers C2 endpoint), with the destination obscured via Buffer.from("bW9tby1yZXN0LmxhcHhhMzU0LndvcmtlcnMuZGV2", "base64").toString() at index.js:43. The package additionally squats common build-tool command names by declaring bin entries for webpack, vite, tsc/tsnode, jest, eslint, gulp, next, turbo, and prettier — all aliased to index.js — and spawns the real local tool (e.g. webpack-cli) afterwards to mask the malicious behavior when invoked via PATH or npx.
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 fhirproxy-utils (version 1.0.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging fhirproxy-utils across your stack and pipelines.
If you installed it — respond
fhirproxy-utils 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 fhirproxy-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 fhirproxy-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 fhirproxy-utils-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.