How to set POST request Binary body for Postman Iterations?

How to process multiple files (from HTTP directory or file system) by Postman + Data File with URLs?

I did:

  1. in Pre-Request, Download and save file into the env variable.
  2. POST Request is in the Raw mode, body is set from env variable.

That not works for binary data - data corrupted
after js.buffer.toString('binary') (Maybe UTF-8 encoded?)

Looking for other solutions.

request body from collection.json:

"body": {
    "mode": "raw",
    "raw": "{{data-binary}}" }

pre-request script:
get url from data file (iterationData) and download file by pm.sendRequest

pm.sendRequest(
    pm.iterationData.get('fileUrl'),
    function (err, res) {
        var buffer = res.stream;
        pm.environment.set('data-binary', 
            buffer.toString('binary'));
    }
);

ps.