Merge pull request #422 from trustar/feat/EN-5047/MISP-manual-update

Feat/en 5047/misp manual update
pull/425/head
Alexandre Dulaunoy 2020-08-11 06:59:33 +02:00 committed by GitHub
commit 7021a0d657
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1 changed files with 113 additions and 30 deletions

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@ -1,8 +1,11 @@
import json import json
import pymisp import pymisp
from base64 import b64encode
from collections import OrderedDict
from . import check_input_attribute, checking_error, standard_error_message from . import check_input_attribute, checking_error, standard_error_message
from pymisp import MISPAttribute, MISPEvent, MISPObject from pymisp import MISPAttribute, MISPEvent, MISPObject
from trustar import TruStar from trustar import TruStar, Indicator
from urllib.parse import quote
misperrors = {'error': "Error"} misperrors = {'error': "Error"}
mispattributes = { mispattributes = {
@ -34,9 +37,13 @@ class TruSTARParser:
'SHA256': "sha256" '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/{}" 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): def __init__(self, attribute, config):
config['enclave_ids'] = config.get('enclave_ids', "").strip().split(',') 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. Returns the MISP Event enriched with TruSTAR indicator summary data.
""" """
try:
event = json.loads(self.misp_event.to_json()) event = json.loads(self.misp_event.to_json())
results = {key: event[key] for key in ('Attribute', 'Object') if (key in event and event[key])} results = {key: event[key] for key in ('Attribute', 'Object') if (key in event and event[key])}
return {'results': results} 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: <str> Type of entity.
:param entity_value: <str> Value of entity. :param entity_value: <str> Value of entity.
:return: <str> Link to indicator report in TruSTAR platform.
""" """
report_links = list() report_id = b64encode(quote(f"{entity_type}|{entity_value}").encode()).decode()
trustar_reports = self.ts_client.search_reports(entity_value)
for report in trustar_reports:
report_links.append(self.REPORT_BASE_URL.format(report.id))
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 Extracts tags from the enrichment report in order to add them
a MISP trustar_report object and adds the summary data and links as attributes. to the TruSTAR MISP Object. Removes tags from report to avoid
redundancy.
:param summaries: <generator> A TruSTAR Python SDK Page.generator object for generating :param: <OrderedDict> Enrichment data.
indicator summaries pages. :return: <list> 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: <trustar.IndicatorSummary> Indicator summary report.
:param metadata: <trustar.Indicator> Indicator metadata report.
:return: <str> 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: <str> Value of the attribute
:summary: <trustar.IndicatorSummary> Indicator summary response object.
:metadata: <trustar.Indicator> Indicator response object.
""" """
for summary in summaries: # Verify that the indicator type is supported by TruSTAR
trustar_obj = MISPObject('trustar_report') if summary and summary.indicator_type in self.ENTITY_TYPE_MAPPINGS:
indicator_type = summary.indicator_type indicator_type = summary.indicator_type
indicator_value = summary.value elif metadata and metadata.type in self.ENTITY_TYPE_MAPPINGS:
if indicator_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], 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", trustar_obj.add_attribute("INDICATOR_SUMMARY", attribute_type="text",
value=json.dumps(summary.to_dict(), sort_keys=True, indent=4)) value=json.dumps(enrichment_report, indent=4))
report_links = self.generate_trustar_links(indicator_value)
for link in report_links: report_link = self.generate_trustar_link(indicator_type, indicator)
trustar_obj.add_attribute("REPORT_LINK", attribute_type="link", value=link) trustar_obj.add_attribute("REPORT_LINK", attribute_type="link", value=report_link)
self.misp_event.add_object(**trustar_obj) 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): def handler(q=False):
@ -117,15 +190,25 @@ def handler(q=False):
if attribute['type'] not in mispattributes['input']: if attribute['type'] not in mispattributes['input']:
return {'error': 'Unsupported attribute type.'} return {'error': 'Unsupported attribute type.'}
trustar_parser = TruSTARParser(attribute, config) trustar_parser = TruSTARParser(attribute, config)
metadata = None
summary = None
try: try:
summaries = list( metadata = trustar_parser.ts_client.get_indicators_metadata([Indicator(value=attribute['value'])])[0]
trustar_parser.ts_client.get_indicator_summaries([attribute['value']], page_size=MAX_PAGE_SIZE))
except Exception as e: 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 return misperrors
trustar_parser.parse_indicator_summary(summaries)
return trustar_parser.get_results() return trustar_parser.get_results()