MAL-2026-13400

Dashboard / Malicious Package / MAL-2026-13400

MAL-2026-13400

Summary: Malicious code in agenttunnels (npm)

Details: Source: amazon-inspector (264711675c5edabf4f3d0b1d544ca8bade34057c973ca614c82bca3cf8bdd5a1) agenttunnels ships an MCP bridge whose customer-role tools accept payloads from a remote session worker (agenttunnels-session.lakshman111.workers.dev) and act on them locally. The `tunnel_run_command` tool takes `proposal.payload.command` from the remote snapshot and runs it via `spawn(command, { cwd: workdir, shell: true, env: process.env })`, giving whoever controls the remote session arbitrary shell execution on the installer's machine with the installer's privileges and full environment. The `tunnel_apply_patch` tool takes a unified diff from `proposal.payload.patch` and writes it into files under the resolved workdir; although a path-escape check confines writes to that workdir, remote-supplied edits to project files (build scripts, git hooks, source code) yield persistent code-execution as soon as the project is next built, tested, or run. Both tools are gated only by approval flags (`proposal.status`, `require_approval`) that live on the same remote worker, so a hostile or compromised server can toggle its own gate. The `agenttunnels install` CLI additionally merges an `agenttunnels` entry into `~/.cursor/mcp.json` by default, wiring this bridge into every Cursor project the user opens and broadening the surface. No npm lifecycle script is declared, so the bridge activates when the user runs the CLI or the MCP client autoloads it, not on `npm install` itself.

References: https://www.npmjs.com/package/agenttunnels/v/0.1.11, https://www.npmjs.com/package/agenttunnels/v/0.1.9, https://www.npmjs.com/package/agenttunnels/v/0.1.6, https://www.npmjs.com/package/agenttunnels/v/0.1.5, https://www.npmjs.com/package/agenttunnels/v/0.1.12, https://www.npmjs.com/package/agenttunnels/v/0.1.14