OpenSSF/OSV advisory MAL-2026-14034 confirms this npm version as malicious. package.json declares a postinstall script that automatically runs on npm install and fetches AWS ECS container task metadata via the ECS_CONTAINER_METADATA_URI_V4 endpoint (task ARN, container names, image names), then POSTs the collected data to a hardcoded ngrok tunnel at https://mourner-slot-explicit.ngrok-free.dev using curl...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in notafollower1 (npm)
Details
package.json declares a postinstall script that automatically runs on npm install and fetches AWS ECS container task metadata via the ECS_CONTAINER_METADATA_URI_V4 endpoint (task ARN, container names, image names), then POSTs the collected data to a hardcoded ngrok tunnel at https://mourner-slot-explicit.ngrok-free.dev using curl. The postinstall also inspects the container image name for substrings matching known security research operators (twbray, packagehound, wiz, oss-dynamic) and labels the payload accordingly, indicating deliberate sandbox and analyst fingerprinting. The destination is an anonymous ngrok tunnel unrelated to any legitimate publisher infrastructure, and the collected data reveals installer-side CI/build/container environment details to a third party.
Decision reason
OpenSSF Malicious Packages via OSV confirms notafollower1@1.0.13 as malicious (MAL-2026-14034): Malicious code in notafollower1 (npm)