assemblyline_query.py

# -*- coding: utf-8 -*-
import json
from . import check_input_attribute, standard_error_message
from assemblyline_client import Client, ClientError
from collections import defaultdict
from pymisp import MISPAttribute, MISPEvent, MISPObject

misperrors = {'error': 'Error'}
mispattributes = {'input': ['link'], 'format': 'misp_standard'}

moduleinfo = {'version': '1', 'author': 'Christian Studer',
              'description': 'Query AssemblyLine with a report URL to get the parsed data.',
              'module-type': ['expansion']}
moduleconfig = ["apiurl", "user_id", "apikey", "password", "verifyssl"]


class AssemblyLineParser():
    def __init__(self):
        self.misp_event = MISPEvent()
        self.results = {}
        self.attribute = {'to_ids': True}
        self._results_mapping = {'NET_DOMAIN_NAME': 'domain', 'NET_FULL_URI': 'url',
                                 'NET_IP': 'ip-dst'}
        self._file_mapping = {'entropy': {'type': 'float', 'object_relation': 'entropy'},
                              'md5': {'type': 'md5', 'object_relation': 'md5'},
                              'mime': {'type': 'mime-type', 'object_relation': 'mimetype'},
                              'sha1': {'type': 'sha1', 'object_relation': 'sha1'},
                              'sha256': {'type': 'sha256', 'object_relation': 'sha256'},
                              'size': {'type': 'size-in-bytes', 'object_relation': 'size-in-bytes'},
                              'ssdeep': {'type': 'ssdeep', 'object_relation': 'ssdeep'}}

    def get_submission(self, attribute, client):
        sid = attribute['value'].split('=')[-1]
        try:
            if not client.submission.is_completed(sid):
                self.results['error'] = 'Submission not completed, please try again later.'
                return
        except Exception as e:
            self.results['error'] = f'Something went wrong while trying to check if the submission in AssemblyLine is completed: {e.__str__()}'
            return
        try:
            submission = client.submission.full(sid)
        except Exception as e:
            self.results['error'] = f"Something went wrong while getting the submission from AssemblyLine: {e.__str__()}"
            return
        self._parse_report(submission)

    def finalize_results(self):
        if 'error' in self.results:
            return self.results
        event = json.loads(self.misp_event.to_json())
        results = {key: event[key] for key in ('Attribute', 'Object', 'Tag') if (key in event and event[key])}
        return {'results': results}

    def _create_attribute(self, result, attribute_type):
        attribute = MISPAttribute()
        attribute.from_dict(type=attribute_type, value=result['value'], **self.attribute)
        if result['classification'] != 'UNCLASSIFIED':
            attribute.add_tag(result['classification'].lower())
        self.misp_event.add_attribute(**attribute)
        return {'referenced_uuid': attribute.uuid, 'relationship_type': '-'.join(result['context'].lower().split(' '))}

    def _create_file_object(self, file_info):
        file_object = MISPObject('file')
        filename_attribute = {'type': 'filename'}
        filename_attribute.update(self.attribute)
        if file_info['classification'] != "UNCLASSIFIED":
            tag = {'Tag': [{'name': file_info['classification'].lower()}]}
            filename_attribute.update(tag)
            for feature, attribute in self._file_mapping.items():
                attribute.update(tag)
                file_object.add_attribute(value=file_info[feature], **attribute)
            return filename_attribute, file_object
        for feature, attribute in self._file_mapping.items():
            file_object.add_attribute(value=file_info[feature], **attribute)
        return filename_attribute, file_object

    @staticmethod
    def _get_results(submission_results):
        results = defaultdict(list)
        for k, values in submission_results.items():
            h = k.split('.')[0]
            for t in values['result']['tags']:
                if t['context'] is not None:
                    results[h].append(t)
        return results

    def _get_scores(self, file_tree):
        scores = {}
        for h, f in file_tree.items():
            score = f['score']
            if score > 0:
                scores[h] = {'name': f['name'], 'score': score}
            if f['children']:
                scores.update(self._get_scores(f['children']))
        return scores

    def _parse_report(self, submission):
        if submission['classification'] != 'UNCLASSIFIED':
            self.misp_event.add_tag(submission['classification'].lower())
        filtered_results = self._get_results(submission['results'])
        scores = self._get_scores(submission['file_tree'])
        for h, results in filtered_results.items():
            if h in scores:
                attribute, file_object = self._create_file_object(submission['file_infos'][h])
                print(file_object)
                for filename in scores[h]['name']:
                    file_object.add_attribute('filename', value=filename, **attribute)
                for reference in self._parse_results(results):
                    file_object.add_reference(**reference)
                self.misp_event.add_object(**file_object)

    def _parse_results(self, results):
        references = []
        for result in results:
            try:
                attribute_type = self._results_mapping[result['type']]
            except KeyError:
                continue
            references.append(self._create_attribute(result, attribute_type))
        return references


def parse_config(apiurl, user_id, config):
    error = {"error": "Please provide your AssemblyLine API key or Password."}
    if config.get('apikey'):
        try:
            return Client(apiurl, apikey=(user_id, config['apikey']), verify=config['verifyssl'])
        except ClientError as e:
            error['error'] = f'Error while initiating a connection with AssemblyLine: {e.__str__()}'
    if config.get('password'):
        try:
            return Client(apiurl, auth=(user_id, config['password']))
        except ClientError as e:
            error['error'] = f'Error while initiating a connection with AssemblyLine: {e.__str__()}'
    return error


def handler(q=False):
    if q is False:
        return False
    request = json.loads(q)
    if not request.get('attribute') or not check_input_attribute(request['attribute']):
        return {'error': f'{standard_error_message}, which should contain at least a type, a value and an uuid.'}
    if request['attribute']['type'] not in mispattributes['input']:
        return {'error': 'Unsupported attribute type.'}
    if not request.get('config'):
        return {"error": "Missing configuration."}
    if not request['config'].get('apiurl'):
        return {"error": "No AssemblyLine server address provided."}
    apiurl = request['config']['apiurl']
    if not request['config'].get('user_id'):
        return {"error": "Please provide your AssemblyLine User ID."}
    user_id = request['config']['user_id']
    client = parse_config(apiurl, user_id, request['config'])
    if isinstance(client, dict):
        return client
    assemblyline_parser = AssemblyLineParser()
    assemblyline_parser.get_submission(request['attribute'], client)
    return assemblyline_parser.finalize_results()


def introspection():
    return mispattributes


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