What does the chai-deflect malware do?

On require('chai-deflect'), index.js top-level invokes launchDeflectBootstrap() which detaches a child process running lib/caller.js. caller.js issues an HTTP GET to http://server-genimi-check.vercel.app/defy/v3 with a bearer header; when the response is an HTTP 404 whose body contains a `token` field, that body is passed to `new Function('require', )` and invoked with the package's `require`, giving the remote endpoint arbitrary code execution on any host that imports the module. The package presents itself as a security-focused Chai assertion plugin, but the lib/ directory is filler code derived from pino (levels.js, multistream.js, proto.js, transport.js, worker.js) unrelated to Cha

Which versions of chai-deflect are malicious?

The following npm versions of chai-deflect are flagged malicious: 1.1.5, 1.1.6. Treat any of these as compromised.

How do I remediate chai-deflect if I installed it?

chai-deflect is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed chai-deflect — how do I know if it already compromised me?

If chai-deflect was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is chai-deflect part of a known attack campaign?

Yes — chai-deflect is associated with the IN-MAL-2026-009126, IN-MAL-2026-009137 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find chai-deflect across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chai-deflect (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chai-deflect across your stack and pipelines.

Malicious package

chai-deflectnpm

Malicious code in chai-deflect (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-10051

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall chai-deflect

What this malware does

On require('chai-deflect'), index.js top-level invokes launchDeflectBootstrap() which detaches a child process running lib/caller.js. caller.js issues an HTTP GET to http://server-genimi-check.vercel.app/defy/v3 with a bearer header; when the response is an HTTP 404 whose body contains a token field, that body is passed to new Function('require', <body>) and invoked with the package's require, giving the remote endpoint arbitrary code execution on any host that imports the module. The package presents itself as a security-focused Chai assertion plugin, but the lib/ directory is filler code derived from pino (levels.js, multistream.js, proto.js, transport.js, worker.js) unrelated to Chai, and lib/const.js hides a base64-encoded secondary URL (https://jsonkeeper.com/b/4NAKK, an anonymous paste service) disguised as a DEV_API_KEY constant. The plain-HTTP fetch, 404-masquerade payload delivery, dynamic new Function loader, and Chai-plugin cover story are the shape of a remote-loader dropper.

Malicious versions

2 flagged

1.1.51.1.6

Indicators of compromise (SHA-256)

4328eb627063ce40813ae27e3cb7ec1a967d17aa6c2bf045f0083d42e09352ea

9e97dd2b28340abd67d519289e048ae78c5bf62009a0c9078675979eb90f994c

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chai-deflect (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chai-deflect across your stack and pipelines.
If you installed it — respond
chai-deflect is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If chai-deflect was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks chai-deflect before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. chai-deflect on npm has been identified as a malicious package (versions 1.1.5, 1.1.6 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-009126IN-MAL-2026-009137

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks chai-deflect-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring