misp-modules/misp_modules/modules/expansion/trustar_enrich.py

222 lines
8.5 KiB
Python

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, Indicator
from urllib.parse import quote
misperrors = {'error': "Error"}
mispattributes = {
'input': ["btc", "domain", "email-src", "filename", "hostname", "ip-src", "ip-dst", "malware-type", "md5", "sha1",
"sha256", "url"], 'format': 'misp_standard'}
moduleinfo = {'version': "0.1", 'author': "Jesse Hedden",
'description': "Enrich data with TruSTAR",
'module-type': ["hover", "expansion"]}
moduleconfig = ["user_api_key", "user_api_secret", "enclave_ids"]
MAX_PAGE_SIZE = 100 # Max allowable page size returned from /1.3/indicators/summaries endpoint
class TruSTARParser:
ENTITY_TYPE_MAPPINGS = {
'BITCOIN_ADDRESS': "btc",
'CIDR_BLOCK': "ip-src",
'CVE': "vulnerability",
'URL': "url",
'EMAIL_ADDRESS': "email-src",
'SOFTWARE': "filename",
'IP': "ip-src",
'MALWARE': "malware-type",
'MD5': "md5",
'REGISTRY_KEY': "regkey",
'SHA1': "sha1",
'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 = f"MISP-{pymisp.__version__}"
def __init__(self, attribute, config):
config['enclave_ids'] = config.get('enclave_ids', "").strip().split(',')
config['client_metatag'] = self.CLIENT_METATAG
self.ts_client = TruStar(config=config)
self.misp_event = MISPEvent()
self.misp_attribute = MISPAttribute()
self.misp_attribute.from_dict(**attribute)
self.misp_event.add_attribute(**self.misp_attribute)
def get_results(self):
"""
Returns the MISP Event enriched with TruSTAR indicator summary data.
"""
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_link(self, entity_type, entity_value):
"""
Generates link to TruSTAR report of entity.
:param entity_type: <str> Type of entity.
:param entity_value: <str> Value of entity.
:return: <str> Link to indicator report in TruSTAR platform.
"""
report_id = b64encode(quote(f"{entity_type}|{entity_value}").encode()).decode()
return self.REPORT_BASE_URL.format(report_id)
@staticmethod
def extract_tags(enrichment_report):
"""
Extracts tags from the enrichment report in order to add them
to the TruSTAR MISP Object. Removes tags from report to avoid
redundancy.
:param: <OrderedDict> Enrichment data.
: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.
"""
# 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
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)
trustar_obj.add_attribute("INDICATOR_SUMMARY", attribute_type="text",
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):
"""
MISP handler function. A user's API key and secret will be retrieved from the MISP
request and used to create a TruSTAR API client. If enclave IDs are provided, only
those enclaves will be queried for data. Otherwise, all of the enclaves a user has
access to will be queried.
"""
if q is False:
return False
request = json.loads(q)
config = request.get('config', {})
if not config.get('user_api_key') or not config.get('user_api_secret'):
misperrors['error'] = "Your TruSTAR API key and secret are required for indicator enrichment."
return misperrors
if not request.get('attribute') or not check_input_attribute(request['attribute'], requirements=('type', 'value')):
return {'error': f'{standard_error_message}, {checking_error}.'}
attribute = request['attribute']
if attribute['type'] not in mispattributes['input']:
return {'error': 'Unsupported attribute type.'}
trustar_parser = TruSTARParser(attribute, config)
metadata = None
summary = None
try:
metadata = trustar_parser.ts_client.get_indicators_metadata([Indicator(value=attribute['value'])])[0]
except Exception as 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 trustar_parser.get_results()
def introspection():
return mispattributes
def version():
moduleinfo['config'] = moduleconfig
return moduleinfo