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MAL-2026-10723

Dashboard / Malicious Package / MAL-2026-10723

MAL-2026-10723

Published: 16 Jul 2026Last Modified: 6 Aug 2026

Summary: Malicious code in @yeaft/webchat-agent (npm)

Details: Source: amazon-inspector (b627f9a4ff0aaacfcd612224f76fe679e9d0a04578519d75516136e7496aad43) The package installs itself as a user-level service (systemd on Linux via service/linux.js, with launchd/PM2 siblings) and, at agent startup, opens a WebSocket to a configured serverUrl (default ws://localhost:3456, overridable via SERVER_URL/config). The WebSocket message router in connection/message-router.js dispatches server-sent frames: `terminal_create` spawns the user's login shell via node-pty (terminal.js: `pty.spawn(shell,...)`) in the agent's workDir, and `terminal_input` writes the server's `msg.data` bytes directly into that PTY, giving whoever controls the server (or an attacker holding AGENT_SECRET / positioned to MITM the WebSocket) an interactive shell as the installing user. An `upgrade_agent` message handled by connection/upgrade.js runs `npm install @yeaft/webchat-agent@latest --registry=https://pkg.yeaft.com/` and spawns a detached script that stops the service, installs the new version, and restarts it, so the remote party can also swap the agent's own code on demand from a publisher-controlled registry. On every startup, index.js additionally git-clones https://github.com/yeaft/yeaft-skills.git from the mutable `main` branch into ~/.claude/plugins/marketplaces/yeaft-skills-dev, chmod 0755 the hook scripts, and writes the plugin as enabled into ~/.claude/settings.json, giving whoever controls that repo the ability to land executable Claude plugin hooks on the next agent boot. The service/linux.js unit also prepends ~/.local/bin and ~/.npm-global/bin to PATH in the service environment. The remote-shell and self-upgrade paths are the package's advertised remote-agent purpose, but by threat-model definition a network-source-to-spawned-PTY dataflow on the installer's host is a backdoor, and the blast radius is full-host code execution as the installing user.

Affected packages

Package

Name: @yeaft/webchat-agent

Purl: pkg:npm/%40yeaft/webchat-agent

Affected ranges

Type: N/A

Events:

Introduced- None

Fixed -None

Affected versions

1.0.171

1.0.199

1.0.325

1.0.376

1.0.189

1.0.283

1.0.252

1.0.238

1.0.243

1.0.282

1.0.216

1.0.184

1.0.352

1.0.329

1.0.361

1.0.281

1.0.217

1.0.188

1.0.312

1.0.350

1.0.253

1.0.355

1.0.300

1.0.206

1.0.257

1.0.226

1.0.337

1.0.309

1.0.273

1.0.311

1.0.269

1.0.289

1.0.258

1.0.222

1.0.374

1.0.224

1.0.351

1.0.336

1.0.335

1.0.242

1.0.307

1.0.172

1.0.228

1.0.219

1.0.321

1.0.249

1.0.211

1.0.371

1.0.368

1.0.244

1.0.262

1.0.344

1.0.180

1.0.237

1.0.334

1.0.323

1.0.250

1.0.315

1.0.298

1.0.354

1.0.227

1.0.332

1.0.274

1.0.182

1.0.378

1.0.245

1.0.369

1.0.192

1.0.194

1.0.220

1.0.338

1.0.296

1.0.232

1.0.367

1.0.202

1.0.310

1.0.324

1.0.341

1.0.308

1.0.255

1.0.364

1.0.198

1.0.204

1.0.247

1.0.277

1.0.290

1.0.203

1.0.263

1.0.201

1.0.254

1.0.288

1.0.278

1.0.349

1.0.183

1.0.235

1.0.175

1.0.260

1.0.365

1.0.285

1.0.239

1.0.295

1.0.353

1.0.331

1.0.193

1.0.384

1.0.185

1.0.342

1.0.240

1.0.304

1.0.246

1.0.287

1.0.292

1.0.173

1.0.264

1.0.359

1.0.195

1.0.316

1.0.377

1.0.234

1.0.267

1.0.210

1.0.270

1.0.314

1.0.363

1.0.181

1.0.221

1.0.293

1.0.233

1.0.214

1.0.373

1.0.333

1.0.200

1.0.356

1.0.190

1.0.207

1.0.284

1.0.317

1.0.294

1.0.272

1.0.186

1.0.271

1.0.348

1.0.191

1.0.357

1.0.213

1.0.347

1.0.265