GCVE-110-OSM-2026-10534

package.json declares a postinstall lifecycle script that runs automatically on `npm install`. The script uses child_process to query the AWS ECS container metadata endpoint (ECS_CONTAINER_METADATA_URI_V4/task), which returns the cluster name, AWS account ID, task ARN, and container image list for the installer's ECS task, then POSTs the response body to the hardcoded ngrok tunnel https://mourner-slot-explicit.ngrok-free.dev via `curl -X POST... --data-binary @-`. The package ships only package.json with no source, build artifacts, or documented functionality, so the postinstall has no legitimate purpose. The destination is an anonymous, mutable ngrok tunnel with no relationship to any publisher — the shape of cloud-environment reconnaissance and exfiltration against AWS ECS installers. Judge assessment: This package is consistent with a cloud-environment reconnaissance and exfiltration implant targeting AWS ECS installers: the hardcoded C2/exfil host `https://mourner-slot-explicit.ngrok-free.dev` is classified as a plaintext C2 URL, and the `npm-postinstall-script` means it runs automatically on install. The OSV advisory specifically describes the postinstall using `child_process` to query `ECS_CONTAINER_METADATA_URI_V4/task` and POST the response to the ngrok tunnel, which is a clear attacker model for stealing container metadata from victim environments. The metadata also fits a throwaway malicious package pattern: a brand-new npm account (`cascacac11111`), a package published within hours, and minimal/no legitimate project metadata. Taken together, this is malicious with very high confidence and should be submitted as a likely supply-chain attack. ENTRY - Postinstall Script in package.json: ""postinstall": "node -e \"" DESTINATION - 2 c2 (urls, domains) (values recorded in verified_iocs) ADDITIONAL FINDINGS - Ngrok Tunneling Service in package.json: "ngrok-free.dev" - Brand New Package - Very New NPM Publisher Account