misp-modules/docs/contribute.md

11 KiB

How to add your own MISP modules?

Create your module in misp_modules/modules/expansion/, misp_modules/modules/export_mod/, or misp_modules/modules/import_mod/. The module should have at minimum three functions:

  • introspection function that returns a dict of the supported attributes (input and output) by your expansion module.
  • handler function which accepts a JSON document to expand the values and return a dictionary of the expanded values.
  • version function that returns a dict with the version and the associated meta-data including potential configurations required of the module.

Don't forget to return an error key and value if an error is raised to propagate it to the MISP user-interface.

Your module's script name should also be added in the __all__ list of <module type folder>/__init__.py in order for it to be loaded.

...
    # Checking for required value
    if not request.get('ip-src'):
        # Return an error message
        return {'error': "A source IP is required"}
...

introspection

The function that returns a dict of the supported attributes (input and output) by your expansion module.

mispattributes = {'input': ['link', 'url'],
                  'output': ['attachment', 'malware-sample']}

def introspection():
    return mispattributes

version

The function that returns a dict with the version and the associated meta-data including potential configurations required of the module.

Additional Configuration Values

If your module requires additional configuration (to be exposed via the MISP user-interface), you can define those in the moduleconfig value returned by the version function.

# config fields that your code expects from the site admin
moduleconfig = ["apikey", "event_limit"]

def version():
    moduleinfo['config'] = moduleconfig
    return moduleinfo

When you do this a config array is added to the meta-data output containing all the potential configuration values:

"meta": {
      "description": "PassiveTotal expansion service to expand values with multiple Passive DNS sources",
      "config": [
        "username",
        "password"
      ],
      "module-type": [
        "expansion",
        "hover"
      ],

...

If you want to use the configuration values set in the web interface they are stored in the key config in the JSON object passed to the handler.

def handler(q=False):

    # Check if we were given a configuration
    config = q.get("config", {})

    # Find out if there is a username field
    username = config.get("username", None)

handler

The function which accepts a JSON document to expand the values and return a dictionary of the expanded values.

def handler(q=False):
    "Fully functional rot-13 encoder"
    if q is False:
        return False
    request = json.loads(q)
    src = request.get('ip-src')
    if src is None:
        # Return an error message
        return {'error': "A source IP is required"}
    else:
        return {'results':
                codecs.encode(src, "rot-13")}

export module

For an export module, the request["data"] object corresponds to a list of events (dictionaries) to handle.

Iterating over events attributes is performed using their Attribute key.

...
for event in request["data"]:
        for attribute in event["Attribute"]:
          # do stuff w/ attribute['type'], attribute['value'], ...
...

### Returning Binary Data

If you want to return a file or other data you need to add a data attribute.

~~~python
{"results": {"values": "filename.txt",
             "types": "attachment",
             "data"  : base64.b64encode(<ByteIO>)  # base64 encode your data first
             "comment": "This is an attachment"}}

If the binary file is malware you can use 'malware-sample' as the type. If you do this the malware sample will be automatically zipped and password protected ('infected') after being uploaded.

{"results": {"values": "filename.txt",
             "types": "malware-sample",
             "data"  : base64.b64encode(<ByteIO>)  # base64 encode your data first
             "comment": "This is an attachment"}}

To learn more about how data attributes are processed you can read the processing code here.

Module type

A MISP module can be of four types:

  • expansion - service related to an attribute that can be used to extend and update an existing event.
  • hover - service related to an attribute to provide additional information to the users without updating the event.
  • import - service related to importing and parsing an external object that can be used to extend an existing event.
  • export - service related to exporting an object, event, or data.

module-type is an array where the list of supported types can be added.

Testing your modules?

MISP uses the modules function to discover the available MISP modules and their supported MISP attributes:

% curl -s http://127.0.0.1:6666/modules | jq .
[
  {
    "name": "passivetotal",
    "type": "expansion",
    "mispattributes": {
      "input": [
        "hostname",
        "domain",
        "ip-src",
        "ip-dst"
      ],
      "output": [
        "ip-src",
        "ip-dst",
        "hostname",
        "domain"
      ]
    },
    "meta": {
      "description": "PassiveTotal expansion service to expand values with multiple Passive DNS sources",
      "config": [
        "username",
        "password"
      ],
      "author": "Alexandre Dulaunoy",
      "version": "0.1"
    }
  },
  {
    "name": "sourcecache",
    "type": "expansion",
    "mispattributes": {
      "input": [
        "link"
      ],
      "output": [
        "link"
      ]
    },
    "meta": {
      "description": "Module to cache web pages of analysis reports, OSINT sources. The module returns a link of the cached page.",
      "author": "Alexandre Dulaunoy",
      "version": "0.1"
    }
  },
  {
    "name": "dns",
    "type": "expansion",
    "mispattributes": {
      "input": [
        "hostname",
        "domain"
      ],
      "output": [
        "ip-src",
        "ip-dst"
      ]
    },
    "meta": {
      "description": "Simple DNS expansion service to resolve IP address from MISP attributes",
      "author": "Alexandre Dulaunoy",
      "version": "0.1"
    }
  }
]

The MISP module service returns the available modules in a JSON array containing each module name along with their supported input attributes.

Based on this information, a query can be built in a JSON format and saved as body.json:

{
  "hostname": "www.foo.be",
  "module": "dns"
}

Then you can POST this JSON format query towards the MISP object server:

curl -s http://127.0.0.1:6666/query -H "Content-Type: application/json" --data @body.json -X POST

The module should output the following JSON:

{
  "results": [
    {
      "types": [
        "ip-src",
        "ip-dst"
      ],
      "values": [
        "188.65.217.78"
      ]
    }
  ]
}

It is also possible to restrict the category options of the resolved attributes by passing a list of categories along (optional):

{
  "results": [
    {
      "types": [
        "ip-src",
        "ip-dst"
      ],
      "values": [
        "188.65.217.78"
      ],
      "categories": [
        "Network activity",
        "Payload delivery"
      ]
    }
  ]
}

For both the type and the category lists, the first item in the list will be the default setting on the interface.

Enable your module in the web interface

For a module to be activated in the MISP web interface it must be enabled in the "Plugin Settings.

Go to "Administration > Server Settings" in the top menu

  • Go to "Plugin Settings" in the top "tab menu bar"
  • Click on the name of the type of module you have created to expand the list of plugins to show your module.
  • Find the name of your plugin's "enabled" value in the Setting Column. "Plugin.[MODULE NAME]_enabled"
  • Double click on its "Value" column
Priority        Setting                         Value   Description                             Error Message
Recommended     Plugin.Import_ocr_enabled       false   Enable or disable the ocr module.       Value not set.
  • Use the drop-down to set the enabled value to 'true'
Priority        Setting                         Value   Description                             Error Message
Recommended     Plugin.Import_ocr_enabled       true   Enable or disable the ocr module.       Value not set.

Set any other required settings for your module

In this same menu set any other plugin settings that are required for testing.

Documentation

In order to provide documentation about some modules that require specific input / output / configuration, the doc directory contains detailed information about the general purpose, requirements, features, input and output of each of these modules:

  • *description - quick description of the general purpose of the module, as the one given by the moduleinfo
  • requirements - special libraries needed to make the module work
  • features - description of the way to use the module, with the required MISP features to make the module give the intended result
  • references - link(s) giving additional information about the format concerned in the module
  • input - description of the format of data used in input
  • output - description of the format given as the result of the module execution

In addition to the modul documentation please add your module to docs/index.md.

Tips for developers creating modules

Download a pre-built virtual image from the MISP training materials.

  • Create a Host-Only adapter in VirtualBox
  • Set your Misp OVA to that Host-Only adapter
  • Start the virtual machine
  • Get the IP address of the virutal machine
  • SSH into the machine (Login info on training page)
  • Go into the misp-modules directory
cd /usr/local/src/misp-modules

Set the git repo to your fork and checkout your development branch. If you SSH'ed in as the misp user you will have to use sudo.

sudo git remote set-url origin https://github.com/YourRepo/misp-modules.git
sudo git pull
sudo git checkout MyModBranch

Remove the contents of the build directory and re-install misp-modules.

sudo rm -fr build/*
sudo pip3 install --upgrade .

SSH in with a different terminal and run misp-modules with debugging enabled.

sudo killall misp-modules
misp-modules -d

In your original terminal you can now run your tests manually and see any errors that arrive

cd tests/
curl -s http://127.0.0.1:6666/query -H "Content-Type: application/json" --data @MY_TEST_FILE.json -X POST
cd ../