webservices.rest-utilsnpm
Advisory published Updated
webservices.rest-utils is a confirmed malicious npm package (MAL-2026-4336) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.5, 1.0.7, 1.0.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in webservices.rest-utils (npm)
What this malware does
package.json declares both preinstall and postinstall hooks that execute index.js, which exfiltrates installer data to a base64-encoded Cloudflare Worker destination (openmrs-sol-dev-v2.lapxa354.workers.dev). The payload includes hostname, username, network interfaces, /etc/resolv.conf,.git/HEAD, ~40 CI/CD environment variables (GITHUB_, GITLAB_, AWS_, CIRCLE_, BUILDKITE_, VERCEL_, etc.), recursively walked package.json metadata,.npmrc registry/scope hints, and presence indicators for ~/.ssh, ~/.aws/credentials, ~/.kube/config, ~/.docker, ~/.npmrc, ~/.gitconfig, shell histories. When cloud env-var probes match, the script contacts the cloud metadata IP (encoded as decimal 2852039166 == 169.254.169.254) to harvest live AWS IMDSv2 IAM tokens, GCP service-account access tokens, and Azure managed-identity tokens — first 40 characters of each are appended to the exfil. It additionally performs DNS reconnaissance against ~25 internal hostnames (kubernetes.default.svc.cluster.local, vault.internal, consul.service.consul, gitlab.local, jenkins.local, ec2.internal, rancher.internal, etc.) for lateral-movement targeting. package.json declares 11 bin aliases — webpack, vite, tsc, eslint, jest, gulp, next, turbo, prettier, tsnode — all pointing at the same malicious index.js, so every subsequent invocation of those common dev commands re-triggers the exfiltrator while forwarding to the real tool to mask the hijack. Obfuscation (base64 destination, decimal-encoded metadata IP, MalekAbuLialaResearch/1.0 cover User-Agent, [Webpack-Debug-MAB-v1] log label) confirms intent.
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
Search your lockfiles and build artifacts for webservices.rest-utils (3 malicious versions).
If you installed it — respond
webservices.rest-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 webservices.rest-utils was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
- ReversingLabs · finder
Detect & block this
O3 blocks webservices.rest-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.