strutil-helpers-corenpm
Advisory published Updated
strutil-helpers-core is a confirmed malicious npm package (MAL-2026-19144) that executes malicious code on install (malicious versions 1.0.1, 1.0.2, 1.0.3…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in strutil-helpers-core (npm)
What this malware does
The package advertises itself as lightweight string utility helpers (trim/capitalize/truncate), but ships a 17KB Linux ELF.node addon, a 434KB Windows PE.node addon, and a 3.7MB opaque.napi_cache data blob none of which are needed for the stated purpose. index.js unconditionally loads the platform-appropriate native addon on every require() and swallows errors silently before the trivial string helpers are even defined. The native addon references the adjacent.napi_cache blob and contains code paths for file I/O, fork/setsid/execlp on Linux and CreateProcessA with a 'node "%s"' command template on Windows, staging decoded JavaScript at /tmp/.<pid> (format string /tmp/.%u, %s.nc%lu.js) and executing it under node. Before firing, the addon enumerates CI and sandbox indicators (GITHUB_ACTIONS, GITLAB_CI, TRAVIS, CIRCLECI, JENKINS_URL, BUILDKITE, CODEBUILD_BUILD_ID, APPVEYOR, SEMAPHORE, TEAMCITY_VERSION, BITBUCKET_BUILD_NUMBER, NETLIFY, VERCEL, CF_BUILD_ID, SCREWDRIVER, SANDBOX), reads /proc/1/cgroup, /proc/1/cmdline, /proc/self/status (TracerPid) and /proc/self/maps for docker/containerd/kubepod/podman markers, and on Windows checks IsDebuggerPresent, CheckRemoteDebuggerPresent and scans running processes for analysis tools (wireshark, httpdebug, Process32First). The combination of a trivial cover-story API, undeclared native binaries loaded silently on import, an opaque sibling blob decrypted to a hidden /tmp staging path and executed under node, and sandbox/CI/debugger evasion gating is a load-time dropper that runs attacker-controlled code on the installer's host as soon as the package is required.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for strutil-helpers-core (5 malicious versions).
If you installed it — respond
Remove strutil-helpers-core from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If strutil-helpers-core 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
Detect & block this
O3 blocks strutil-helpers-core-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.