diff --git a/misp_modules/modules/expansion/trustar_enrich.py b/misp_modules/modules/expansion/trustar_enrich.py index a0d6177..ab472af 100644 --- a/misp_modules/modules/expansion/trustar_enrich.py +++ b/misp_modules/modules/expansion/trustar_enrich.py @@ -1,8 +1,11 @@ import json import pymisp +from base64 import b64encode +from collections import OrderedDict from . import check_input_attribute, checking_error, standard_error_message from pymisp import MISPAttribute, MISPEvent, MISPObject -from trustar import TruStar +from trustar import TruStar, Indicator +from urllib.parse import quote misperrors = {'error': "Error"} mispattributes = { @@ -34,9 +37,13 @@ class TruSTARParser: 'SHA256': "sha256" } + # Relevant fields from each TruSTAR endpoint + SUMMARY_FIELDS = ["severityLevel", "source", "score", "attributes"] + METADATA_FIELDS = ["sightings", "first_seen", "last_seen", "tags"] + REPORT_BASE_URL = "https://station.trustar.co/constellation/reports/{}" - CLIENT_METATAG = "MISP-{}".format(pymisp.__version__) + CLIENT_METATAG = f"MISP-{pymisp.__version__}" def __init__(self, attribute, config): config['enclave_ids'] = config.get('enclave_ids', "").strip().split(',') @@ -52,45 +59,111 @@ class TruSTARParser: """ Returns the MISP Event enriched with TruSTAR indicator summary data. """ - event = json.loads(self.misp_event.to_json()) - results = {key: event[key] for key in ('Attribute', 'Object') if (key in event and event[key])} - return {'results': results} + try: + event = json.loads(self.misp_event.to_json()) + results = {key: event[key] for key in ('Attribute', 'Object') if (key in event and event[key])} + return {'results': results} + except Exception as e: + misperrors['error'] += f" -- Encountered issue serializing enrichment data -- {e}" + return misperrors - def generate_trustar_links(self, entity_value): + def generate_trustar_link(self, entity_type, entity_value): """ - Generates links to TruSTAR reports if they exist. + Generates link to TruSTAR report of entity. + :param entity_type: Type of entity. :param entity_value: Value of entity. + :return: Link to indicator report in TruSTAR platform. """ - report_links = list() - trustar_reports = self.ts_client.search_reports(entity_value) - for report in trustar_reports: - report_links.append(self.REPORT_BASE_URL.format(report.id)) + report_id = b64encode(quote(f"{entity_type}|{entity_value}").encode()).decode() - return report_links + return self.REPORT_BASE_URL.format(report_id) - def parse_indicator_summary(self, summaries): + @staticmethod + def extract_tags(enrichment_report): """ - Converts a response from the TruSTAR /1.3/indicators/summaries endpoint - a MISP trustar_report object and adds the summary data and links as attributes. + Extracts tags from the enrichment report in order to add them + to the TruSTAR MISP Object. Removes tags from report to avoid + redundancy. - :param summaries: A TruSTAR Python SDK Page.generator object for generating - indicator summaries pages. + :param: Enrichment data. + :return: List of tags. + """ + if enrichment_report and enrichment_report.get('tags'): + return [tag.get('name') for tag in enrichment_report.pop('tags')] + return None + + def generate_enrichment_report(self, summary, metadata): + """ + Extracts desired fields from summary and metadata reports and + generates an enrichment report. + + :param summary: Indicator summary report. + :param metadata: Indicator metadata report. + :return: Enrichment report. + """ + # Preserve order of fields as they exist in SUMMARY_FIELDS and METADATA_FIELDS + enrichment_report = OrderedDict() + + if summary: + summary_dict = summary.to_dict() + enrichment_report.update( + {field: summary_dict[field] for field in self.SUMMARY_FIELDS if summary_dict.get(field)}) + + if metadata: + metadata_dict = metadata.to_dict() + enrichment_report.update( + {field: metadata_dict[field] for field in self.METADATA_FIELDS if metadata_dict.get(field)}) + + return enrichment_report + + def parse_indicator_summary(self, indicator, summary, metadata): + """ + Pulls enrichment data from the TruSTAR /indicators/summaries and /indicators/metadata endpoints + and creates a MISP trustar_report. + + :param indicator: Value of the attribute + :summary: Indicator summary response object. + :metadata: Indicator response object. """ - for summary in summaries: - trustar_obj = MISPObject('trustar_report') + # Verify that the indicator type is supported by TruSTAR + if summary and summary.indicator_type in self.ENTITY_TYPE_MAPPINGS: indicator_type = summary.indicator_type - indicator_value = summary.value - if indicator_type in self.ENTITY_TYPE_MAPPINGS: + elif metadata and metadata.type in self.ENTITY_TYPE_MAPPINGS: + indicator_type = metadata.type + else: + misperrors['error'] += " -- Attribute not found or not supported" + raise Exception + + try: + # Extract most relevant fields from indicator summary and metadata responses + enrichment_report = self.generate_enrichment_report(summary, metadata) + tags = self.extract_tags(enrichment_report) + + if enrichment_report: + # Create MISP trustar_report object and populate it with enrichment data + trustar_obj = MISPObject('trustar_report') trustar_obj.add_attribute(indicator_type, attribute_type=self.ENTITY_TYPE_MAPPINGS[indicator_type], - value=indicator_value) + value=indicator) trustar_obj.add_attribute("INDICATOR_SUMMARY", attribute_type="text", - value=json.dumps(summary.to_dict(), sort_keys=True, indent=4)) - report_links = self.generate_trustar_links(indicator_value) - for link in report_links: - trustar_obj.add_attribute("REPORT_LINK", attribute_type="link", value=link) + value=json.dumps(enrichment_report, indent=4)) + + report_link = self.generate_trustar_link(indicator_type, indicator) + trustar_obj.add_attribute("REPORT_LINK", attribute_type="link", value=report_link) + self.misp_event.add_object(**trustar_obj) + elif not tags: + # If enrichment report is empty and there are no tags, nothing to add to attribute + raise Exception("No relevant data found") + + if tags: + for tag in tags: + self.misp_event.add_attribute_tag(tag, indicator) + + except Exception as e: + misperrors['error'] += f" -- Error enriching attribute {indicator} -- {e}" + raise e def handler(q=False): @@ -117,15 +190,25 @@ def handler(q=False): if attribute['type'] not in mispattributes['input']: return {'error': 'Unsupported attribute type.'} trustar_parser = TruSTARParser(attribute, config) + metadata = None + summary = None try: - summaries = list( - trustar_parser.ts_client.get_indicator_summaries([attribute['value']], page_size=MAX_PAGE_SIZE)) + metadata = trustar_parser.ts_client.get_indicators_metadata([Indicator(value=attribute['value'])])[0] except Exception as e: - misperrors['error'] = "Unable to retrieve TruSTAR summary data: {}".format(e) + misperrors['error'] += f" -- Could not retrieve indicator metadata from TruSTAR {e}" + + try: + summary = list( + trustar_parser.ts_client.get_indicator_summaries([attribute['value']], page_size=MAX_PAGE_SIZE))[0] + except Exception as e: + misperrors['error'] += f" -- Unable to retrieve TruSTAR summary data: {e}" + + try: + trustar_parser.parse_indicator_summary(attribute['value'], summary, metadata) + except Exception: return misperrors - trustar_parser.parse_indicator_summary(summaries) return trustar_parser.get_results()