Tutorial: Basic Reputation Change Callback Example

This sample demonstrates registering a callback with the DXL fabric to receive reputation change events sent by the McAfee Threat Intelligence Exchange (TIE) DXL service when the reputation of a file or certificate changes.

Prerequisites

• The samples configuration step has been completed (see Samples).
• A McAfee Threat Intelligence Exchange (TIE) Service is available on the DXL fabric.

Running

To run this sample execute the sample/basic/basic-reputation-change-callback-example.js script as follows:

$ node sample/basic/basic-reputation-change-callback-example.js

The output should appear similar to the following:

Waiting for reputation change events...

At this point the sample is listening for both file and certificate reputation events from the DXL fabric.

Force Reputation Change

The next step is to force a reputation change for a file or certificate via ePO. The steps to accomplish this are listed below:

• Open ePO and navigate to the "TIE Reputations" page.

• Select the "File Search" or "Certificate Search" tab.

• Select a file or certificate in the list.

• Click the "Actions" button at the bottom left and select a new "Enterprise" reputation (for example, Known Trusted).

  • NOTE: It is safest to select a file (or certificate) that has a "GTI" Reputation of Known Trusted and simply set the "Enterprise" reputation to be the same (Known Trusted).

• Remove the override by clicking on the "Actions" button again and selecting "Remove Override".

Reputation Change Output

After the reputation change has occurred the reputation change information should appear within the console that the sample is running (similar to the output below):

Reputation change on topic: /mcafee/event/tie/file/repchange/broadcast
{
    "hashes": {
        "md5": "f2c7bb8acc97f92e987a2d4087d01221",
        "sha1": "7eb0139d2175739b3ccb0d1110067820be6abd2b"
    },
    "newReputations": {
        "1": {
            "attributes": {
                "2120340": "0"
            },
            "createDate": 1480551590,
            "providerId": 1,
            "trustLevel": 0
        },
        "3": {
            "attributes": {
                "2101652": "0",
                "2102165": "1480551374",
                "2111893": "244",
                "2114965": "1",
                "2139285": "73183493944770750"
            },
            "createDate": 1480551374,
            "providerId": 3,
            "trustLevel": 99
        }
    },
    "oldReputations": {
        "1": {
            "attributes": {
                "2120340": "0"
            },
            "createDate": 1480551590,
            "providerId": 1,
            "trustLevel": 0
        },
        "3": {
            "attributes": {
                "2101652": "0",
                "2102165": "1480551374",
                "2111893": "244",
                "2114965": "1",
                "2139285": "73183493944770750"
            },
            "createDate": 1480551374,
            "providerId": 3,
            "trustLevel": 0
        }
    },
    "updateTime": 1481222923
}

The first line displays the DXL topic that the event was received on. In this particular case it is "/mcafee/event/tie/file/repchange/broadcast", which indicates that this is a file reputation change event.

The reputation change information is separated into 4 distinct sections:

Hash values

An array of hashes that identify the file or certificate whose reputation has changed.

New reputations

The new Reputations for the file or certificate whose reputation has changed, as an object.

Old reputations

The previous Reputations for the file or certificate whose reputation has changed, as an object.

Change time

The time the reputation change occurred.

Details

The majority of the sample code is shown below:

// Create the client
var client = new dxl.Client(config)

// Define the callback to receive reputation change events
var repChangeCallback = function (repChangeObj, originalEvent) {
  // Display the DXL topic that the event was received on
  console.log('Reputation change on topic: ' +
    originalEvent.destinationTopic)
  // Dump the reputation change info
  console.log(MessageUtils.objectToJson(repChangeObj, true))
}

// Connect to the fabric, supplying a callback function which is invoked
// when the connection has been established
client.connect(function () {
  // Create the McAfee Threat Intelligence Exchange (TIE) client
  var tieClient = new TieClient(client)

  // Register callbacks with client to receive both file and certificate
  // reputation change events
  tieClient.addFileReputationChangeCallback(repChangeCallback)
  tieClient.addCertificateReputationChangeCallback(repChangeCallback)

  // Wait forever
  console.log('Waiting for reputation change events...')
})

A callback function, repChangeCallback, is defined for handling reputation change events. When a reputation change event occurs, this function will display the topic that the event was received on. The reputation change details are printed by converting the repChangeObj object to JSON with a call to the MessageUtils.objectToJson() method.

Once a connection is established to the DXL fabric, the callback function supplied to the DXL client instance's connect() method will be invoked. From within the callback function, a TieClient instance is created. The TieClient instance will be used to communicate with the TIE DXL services.

Next, a call is made to both the addFileReputationChangeCallback() and addCertificateReputationChangeCallback() methods on the TieClient instance to register the repChangeCallback function to be invoked when file and certificate reputation change events occur.