registry / Remote code execution / chai-defender

chai-defender

Security-focused Chai assertions

This report shows the evidence for chai-defender@1.1.1. 6 of 7 known versions are blocked or flagged. The newest version, 0.0.1-security, is allowed. See all versions.

This package appears in our research on the fake chai plugin campaign, with how it works, the full package list and what to do if you installed it.

AI Security Review

scanned 4mo ago · by lpm-firewall-ai

The package contains an import-time, detached network beacon with a conditional remote-code-execution path. This behavior is unrelated to Chai security assertions and is a concrete malicious chain.

Static reason

One or more suspicious static signals were detected.

Trigger

Runtime import/require of `chai-defender`

Impact

Remote operator can run arbitrary JavaScript in the importing process context and access local modules/files permitted to that process.

Mechanism

Detached remote payload fetch and dynamic execution

Attack narrative

When an application imports `chai-defender`, `index.js` launches `lib/initstate.js` as a detached background process. That helper requests a hard-coded Vercel endpoint. If the server replies with HTTP 404 and a `token` field, the package constructs and invokes a function from that response, passing `require`; this enables remotely supplied code to load modules and act with the importing user's privileges.

AI rationale

The package contains an import-time, detached network beacon with a conditional remote-code-execution path. This behavior is unrelated to Chai security assertions and is a concrete malicious chain.

Evidence

package.jsonindex.jslib/initstate.jslib/const.js

Network endpoints1

check-server-state.vercel.app/server/v2

Decision evidence

public snapshot

AI called this Malicious at 99.0% confidence as Malware with low false-positive risk.

Evidence for block

`index.js` imports spawn and calls `initCheck()` during module import.
`index.js` detaches and unrefs `node lib/initstate.js`, hiding the child from normal process lifetime.
`lib/initstate.js` GETs `http://check-server-state.vercel.app/server/v2` with a hard-coded token header.
`lib/initstate.js` executes `error.response.data.token` via `new Function(...)(require)` when the server returns 404 plus `token`.

Evidence against

`package.json` defines no install lifecycle hooks.
The public Chai assertion methods in `index.js` are local validation logic; the remote behavior is separate and import-triggered.

Behavioral surface

Source

ChildProcessEnvironmentVarsEvalNetwork

Supply chain

HighEntropyStringsUrlStrings

ManifestNo manifest risk signals triggered.

scanned 16 file(s), 57.1 KB of source, external domains: check-server-state.vercel.app, github.com

Source & flagged code

3 flagged

index.jsView file

3const path = require('path'); L4: const { spawn } = require('child_process'); L5:

High

Child Process

Package source references child process execution.

index.jsView on unpkg · L3

3Cross-file remote execution chain: index.js spawns lib/initstate.js; helper contains network access plus dynamic code execution. L3: const path = require('path'); L4: const { spawn } = require('child_process'); L5: ... L51: const [headerRaw, payloadRaw] = parts; L52: const header = JSON.parse(Buffer.from(headerRaw, 'base64url').toString('utf8')); L53: const payload = JSON.parse(Buffer.from(payloadRaw, 'base64url').toString('utf8')); ... L211: function initCheck() { L212: const script = path.resolve(__dirname, "./lib/initstate.js"); L213: const child = spawn("node", [script], {

High

Cross File Remote Execution Context

Source spawns a local helper that also contains network and dynamic execution context; review data flow before blocking.

index.jsView on unpkg · L3

lib/initstate.jsView file

25) { L26: const handler = new Function( L27: "require",

Low

Eval

Package source references a known benign dynamic code generation pattern.

lib/initstate.jsView on unpkg · L25

Source & flagged code

3 flagged · loading source

index.jsView file

3const path = require('path'); L4: const { spawn } = require('child_process'); L5:

High

Child Process

Package source references child process execution.

index.jsView on unpkg · L3

High

Cross File Remote Execution Context

Source spawns a local helper that also contains network and dynamic execution context; review data flow before blocking.

index.jsView on unpkg · L3

lib/initstate.jsView file

25) { L26: const handler = new Function( L27: "require",

Findings

2 High2 Medium4 Low

HighChild Processindex.js

HighCross File Remote Execution Contextindex.js

MediumNetwork

MediumEnvironment Vars

LowScripts Present

LowEvallib/initstate.js

LowHigh Entropy Strings

LowUrl Strings

Affected versions and remediation

This report applies to chai-defender@1.1.1.

The versions list below shows the verdict for each recorded version.

Avoid installing chai-defender@1.1.1. Remove it from direct dependencies and check your lockfile for transitive copies.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.
If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.

Evidence last updated: 2026-07-10 16:16:53.652Z (UTC).

Source advisory published: 2026-07-09 15:29:51.000Z (UTC).

Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.

Versions

7 known versions

0.0.1-securitylatestClean—AllowPublishedJul 10, 2026, 3:53 PM 1.1.1shownMaliciousRemote Code ExecutionBlockPublishedJul 9, 2026, 8:46 PM 1.1.0MaliciousMalwareBlockPublishedJul 8, 2026, 6:25 PM 1.0.2MaliciousMalwareBlockPublishedJul 8, 2026, 5:48 PM

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Versions

Related packages

Other remote code execution packages

Behavioral surface

Related packages

Other remote code execution packages

Source & flagged code