Assess the system running postinstall
OpenSSF/OSV advisory MAL-2026-15625 confirms this npm version as malicious. The package's postinstall lifecycle hook pipes the output of `env` through `nc` to a host reconstructed at install time from the package version string via `cut -b 2-4` and `cut -b 5-`. For version 4127000.0.1 the destination decodes to 127.0.0.1:888; the sibling artifact evilpostinstall-192.168.1.100.tgz uses the same slicing scheme to target 192.168.1.100...
Install-time lifecycle script matches a deterministic static-gate block pattern.
package.jsonView on unpkgPackage defines install-time lifecycle scripts.
package.jsonView on unpkgPackage ships compressed or archive-like blobs.
evilpostinstall-192.168.1.100.tgzView on unpkgPackage ships a nested archive or MCP bundle that was inventoried but not recursively analyzed.
evilpostinstall-192.168.1.100.tgzView on unpkgInstall-time lifecycle script matches a deterministic static-gate block pattern.
package.jsonView on unpkg · L8Package defines install-time lifecycle scripts.
package.jsonView on unpkg · L8Package ships compressed or archive-like blobs.
evilpostinstall-192.168.1.100.tgzView on unpkgPackage ships a nested archive or MCP bundle that was inventoried but not recursively analyzed.
evilpostinstall-192.168.1.100.tgzView on unpkg