@iobandamwer/cache-helpernpm

The package advertises itself as 'Cache utilities' but ships no source, no binding.gyp, and no build configuration — only two prebuilt native addons (addon.node ELF for Linux, addon_win.node PE for Windows) and a 4,164,844-byte opaque, high-entropy file named.napi_cache with no readable strings and no magic header. The package.json postinstall hook runs node -e "try{require(process.platform==='win32'?'./addon_win.node':'./addon.node').init()}catch(e){}", loading the platform-specific native binary and invoking init() on every install, with the error swallowed to suppress install-time noise. The Linux addon contains the format string '%s/.napi_cache' alongside fopen64/fread, references a '/tmp/.%u' staging path, and uses fork, setsid, execlp, chmod and _exit primitives — the shape of a drop-and-detach loader that reads the bundled.napi_cache blob, writes it to a hidden /tmp path, chmods it executable and runs it as a detached process. The addon also encodes an extensive evasion suite: environment checks for GITHUB_ACTIONS, GITLAB_CI, TRAVIS, CIRCLECI, JENKINS_URL, BUILDKITE, CODEBUILD_BUILD_ID, APPVEYOR, SEMAPHORE, TEAMCITY_VERSION, BITBUCKET_BUILD_NUMBER, NETLIFY, VERCEL, CF_BUILD_ID and SANDBOX; container probes against /proc/1/cgroup, docker, containerd, kubepod and podman; a TracerPid: debugger check via /proc/self/status; and host fingerprinting through /proc/meminfo, /proc/cpuinfo and /proc/self/maps. The combination — hollow self-description, source-less native binaries, lifecycle-hook execution of a staged opaque payload, and CI/sandbox/debugger gating — has no overlap with any legitimate cache library and is the fingerprint of an install-time dropper for attacker-controlled code.

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.