Code

Plugins

Plugins are supported in several places: Event Processing and the REST api.

Event Processing

The front-end event processing portion of MozDef supports python mq plugins to allow customization of the input chain. Plugins are simple python modules than can register for events with a priority, so they only see events with certain dictionary items/values and will get them in a predefined order.

To create a plugin, make a python class that presents a registration dictionary and a priority as follows:

class message(object):
    def __init__(self):
        '''register our criteria for being passed a message
           as a list of lower case strings or values to match with an event's dictionary of keys or values
           set the priority if you have a preference for order of plugins to run.
           0 goes first, 100 is assumed/default if not sent
        '''
        self.registration = ['sourceipaddress', 'destinationipaddress']
        self.priority = 20

Message Processing

To process a message, define an onMessage function within your class as follows:

def onMessage(self, message, metadata):
    #do something interesting with the message or metadata
    return (message, metadata)

The plugin will receive a copy of the incoming event as a python dictionary in the ‘message’ variable. The plugin can do whatever it wants with this dictionary and return it to MozDef. Plugins will be called in priority order 0 to 100 if the incoming event matches their registration criteria. i.e. If you register for sourceipaddress you will only get events containing the sourceipaddress field.

If you return the message as None (i.e. message=None) the message will be dropped and not be processed any further. If you modify the metadata the new values will be used when the message is posted to elastic search. You can use this to assign custom document types, set static document _id values, etc.

Plugin Registration

Simply place the .py file in the plugins directory where the esworker.py is located, restart the esworker.py process and it will recognize the plugin and pass it events as it sees them.

REST Plugins

The REST API for MozDef also supports rest plugins which allow you to customize your handling of API calls to suit your environment. Plugins are simple python modules than can register for REST endpoints with a priority, so they only see calls for that endpoint and will get them in a predefined order.

To create a REST API plugin simply create a python class that presents a registration dictionary and priority as follows:

class message(object):
    def __init__(self):
        '''register our criteria for being passed a message
           as a list of lower case strings to match with an rest endpoint
           (i.e. blockip matches /blockip)
           set the priority if you have a preference for order of plugins
           0 goes first, 100 is assumed/default if not sent

           Plugins will register in Meteor with attributes:
           name: (as below)
           description: (as below)
           priority: (as below)
           file: "plugins.filename" where filename.py is the plugin code.

           Plugin gets sent main rest options as:
           self.restoptions
           self.restoptions['configfile'] will be the .conf file
           used by the restapi's index.py file.

        '''

        self.registration = ['blockip']
        self.priority = 10
        self.name = "Banhammer"
        self.description = "BGP Blackhole"

The registration is the REST endpoint for which your plugin will receive a copy of the request/response objects to use or modify. The priority allows you to order your plugins if needed so that they operate on data in a defined pattern. The name and description are passed to the Meteor UI for use in dialog boxes, etc so the user can make choices when needed to include/exclude plugins. For example the /blockip endpoint allows you to register multiple methods of blocking an IP to match your environment: firewalls, BGP tables, DNS blackholes can all be independently implemented and chosen by the user at run time.

Message Processing

To process a message, define an onMessage function within your class as follows:

def onMessage(self, request, response):
    '''
    request: http://bottlepy.org/docs/dev/api.html#the-request-object
    response: http://bottlepy.org/docs/dev/api.html#the-response-object

    '''
    response.headers['X-PLUGIN'] = self.description

It’s a good idea to add your plugin to the response headers if it acts on a message to facilitate troubleshooting. Other than that, you are free to perform whatever processing you need within the plugin being sure to return the request, response object once done:

return (request, response)

Plugin Registration

Simply place the .py file in the rest/plugins directory, restart the REST API process and it will recognize the plugin and pass it events as it sees them.

Alert Plugins

The alert pipeline also supports alert plugins which allow you to modify an alert’s properties while the alert is “firing” (before it is saved into Elasticsearch/sent to alert actions).

Create a sample plugin in alerts/plugins:

class message(object):
    def __init__(self):
        '''
        adds a new field 'testing'
        to the alert if sourceipaddress is 127.0.0.1
        '''

        self.registration = "sourceipaddress"
        self.priority = 1

This plugin’s onMessage function will get executed every time an alert has “sourceipaddress” as either a key or a value.

Message Processing

To process a message, define an onMessage function within your class as follows:

def onMessage(self, message):
    if 'sourceipaddress' in message && message['sourceipaddress'] == '127.0.0.1':
        message['testing'] = True
    return message

It’s worth noting that this is a blocking mechanism, so if this function is reaching out to external resources, the alert will not “fire” until it’s execution has finished. It may be preferred to use an alert action instead in cases where you don’t need to modify the alert, but want to trigger an API somewhere.

Plugin Registration

Simply place the .py file in the alerts/plugins directory, restart the alerts process and it will recognize the plugin and pass it alerts based on registration.

Actions

Actions are currently supported at the end of the alert pipeline.

Alert Action Processing

Alert actions run at the very end of the alert pipeline after the alert is already created, and are non blocking (meaning they also don’t have the ability to modify alerts inline).

class message(object):
    def __init__(self):
        '''
        triggers when a geomodel alert is generated
        '''
        self.alert_classname = 'AlertGeomodel'
        self.registration = 'geomodel'
        self.priority = 1

Alert Trigger

def onMessage(self, message):
    print(message)
    return message

Plugin Registration

Simply place the .py file in the alert actions directory.