import json import logging import vt from . import check_input_attribute, standard_error_message from urllib.parse import urlparse from pymisp import MISPAttribute, MISPEvent, MISPObject misperrors = {'error': 'Error'} mispattributes = {'input': ['hostname', 'domain', "ip-src", "ip-dst", "md5", "sha1", "sha256", "url"], 'format': 'misp_standard'} moduleinfo = {'version': '2', 'author': 'Christian Studer', 'description': 'Enrich observables with the VirusTotal v3 public API', 'module-type': ['expansion', 'hover']} moduleconfig = ['apikey', 'proxy_host', 'proxy_port', 'proxy_username', 'proxy_password'] LOGGER = logging.getLogger('virus_total_public') LOGGER.setLevel(logging.INFO) DEFAULT_RESULTS_LIMIT = 10 class VirusTotalParser: def __init__(self, client: vt.Client, limit: int) -> None: self.client = client self.limit = limit or DEFAULT_RESULTS_LIMIT self.misp_event = MISPEvent() self.attribute = MISPAttribute() self.parsed_objects = {} self.input_types_mapping = {'ip-src': self.parse_ip, 'ip-dst': self.parse_ip, 'domain': self.parse_domain, 'hostname': self.parse_domain, 'md5': self.parse_hash, 'sha1': self.parse_hash, 'sha256': self.parse_hash, 'url': self.parse_url} self.proxies = None @staticmethod def get_total_analysis(analysis: dict, known_distributors: dict = None) -> int: if not analysis: return 0 count = sum([analysis['undetected'], analysis['suspicious'], analysis['harmless']]) return count if known_distributors else count + analysis['malicious'] def query_api(self, attribute: dict) -> None: self.attribute.from_dict(**attribute) self.input_types_mapping[self.attribute.type](self.attribute.value) def get_result(self) -> dict: 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} def add_vt_report(self, report: vt.Object) -> str: analysis = report.get('last_analysis_stats') total = self.get_total_analysis(analysis, report.get('known_distributors')) permalink = f'https://www.virustotal.com/gui/{report.type}/{report.id}' vt_object = MISPObject('virustotal-report') vt_object.add_attribute('permalink', type='link', value=permalink) detection_ratio = f"{analysis['malicious']}/{total}" if analysis else '-/-' vt_object.add_attribute('detection-ratio', type='text', value=detection_ratio, disable_correlation=True) self.misp_event.add_object(**vt_object) return vt_object.uuid def create_misp_object(self, report: vt.Object) -> MISPObject: misp_object = None vt_uuid = self.add_vt_report(report) if report.type == 'file': misp_object = MISPObject('file') for hash_type in ('md5', 'sha1', 'sha256', 'tlsh', 'vhash', 'ssdeep', 'imphash'): misp_object.add_attribute(**{'type': hash_type, 'object_relation': hash_type, 'value': report.get(hash_type)}) elif report.type == 'domain': misp_object = MISPObject('domain-ip') misp_object.add_attribute('domain', type='domain', value=report.id) elif report.type == 'ip_address': misp_object = MISPObject('domain-ip') misp_object.add_attribute('ip', type='ip-dst', value=report.id) elif report.type == 'url': misp_object = MISPObject('url') misp_object.add_attribute('url', type='url', value=report.url) misp_object.add_reference(vt_uuid, 'analyzed-with') return misp_object ################################################################################ #### Main parsing functions #### # noqa ################################################################################ def parse_domain(self, domain: str) -> str: domain_report = self.client.get_object(f'/domains/{domain}') # DOMAIN domain_object = self.create_misp_object(domain_report) # WHOIS if domain_report.whois: whois_object = MISPObject('whois') whois_object.add_attribute('text', type='text', value=domain_report.whois) self.misp_event.add_object(**whois_object) # SIBLINGS AND SUBDOMAINS for relationship_name, misp_name in [('siblings', 'sibling-of'), ('subdomains', 'subdomain')]: rel_iterator = self.client.iterator(f'/domains/{domain_report.id}/{relationship_name}', limit=self.limit) for item in rel_iterator: attr = MISPAttribute() attr.from_dict(**dict(type='domain', value=item.id)) self.misp_event.add_attribute(**attr) domain_object.add_reference(attr.uuid, misp_name) # RESOLUTIONS resolutions_iterator = self.client.iterator(f'/domains/{domain_report.id}/resolutions', limit=self.limit) for resolution in resolutions_iterator: domain_object.add_attribute('ip', type='ip-dst', value=resolution.ip_address) # COMMUNICATING AND REFERRER FILES for relationship_name, misp_name in [ ('communicating_files', 'communicates-with'), ('referrer_files', 'referring') ]: files_iterator = self.client.iterator(f'/domains/{domain_report.id}/{relationship_name}', limit=self.limit) for file in files_iterator: file_object = self.create_misp_object(file) file_object.add_reference(domain_object.uuid, misp_name) self.misp_event.add_object(**file_object) self.misp_event.add_object(**domain_object) return domain_object.uuid def parse_hash(self, file_hash: str) -> str: file_report = self.client.get_object(f'/files/{file_hash}') file_object = self.create_misp_object(file_report) # COMMUNICATING, DOWNLOADED AND REFERRER FILES for relationship_name, misp_name in [ ('contacted_urls', 'communicates-with'), ('contacted_domains', 'communicates-with'), ('contacted_ips', 'communicates-with') ]: files_iterator = self.client.iterator(f'/files/{file_report.id}/{relationship_name}', limit=self.limit) for file in files_iterator: file_object = self.create_misp_object(file) file_object.add_reference(file_object.uuid, misp_name) self.misp_event.add_object(**file_object) self.misp_event.add_object(**file_object) return file_object.uuid def parse_ip(self, ip: str) -> str: ip_report = self.client.get_object(f'/ip_addresses/{ip}') # IP ip_object = self.create_misp_object(ip_report) # ASN asn_object = MISPObject('asn') asn_object.add_attribute('asn', type='AS', value=ip_report.asn) asn_object.add_attribute('subnet-announced', type='ip-src', value=ip_report.network) asn_object.add_attribute('country', type='text', value=ip_report.country) self.misp_event.add_object(**asn_object) # RESOLUTIONS resolutions_iterator = self.client.iterator(f'/ip_addresses/{ip_report.id}/resolutions', limit=self.limit) for resolution in resolutions_iterator: ip_object.add_attribute('domain', type='domain', value=resolution.host_name) self.misp_event.add_object(**ip_object) return ip_object.uuid def parse_url(self, url: str) -> str: url_id = vt.url_id(url) url_report = self.client.get_object(f'/urls/{url_id}') url_object = self.create_misp_object(url_report) self.misp_event.add_object(**url_object) return url_object.uuid def get_proxy_settings(config: dict) -> dict: """Returns proxy settings in the requests format. If no proxy settings are set, return None.""" proxies = None host = config.get('proxy_host') port = config.get('proxy_port') username = config.get('proxy_username') password = config.get('proxy_password') if host: if not port: misperrors['error'] = 'The virustotal_proxy_host config is set, ' \ 'please also set the virustotal_proxy_port.' raise KeyError parsed = urlparse(host) if 'http' in parsed.scheme: scheme = 'http' else: scheme = parsed.scheme netloc = parsed.netloc host = f'{netloc}:{port}' if username: if not password: misperrors['error'] = 'The virustotal_proxy_username config is set, ' \ 'please also set the virustotal_proxy_password.' raise KeyError auth = f'{username}:{password}' host = auth + '@' + host proxies = { 'http': f'{scheme}://{host}', 'https': f'{scheme}://{host}' } return proxies def parse_error(status_code: int) -> str: status_mapping = {204: 'VirusTotal request rate limit exceeded.', 400: 'Incorrect request, please check the arguments.', 403: 'You don\'t have enough privileges to make the request.'} if status_code in status_mapping: return status_mapping[status_code] return "VirusTotal may not be accessible." def handler(q=False): if q is False: return False request = json.loads(q) if not request.get('config') or not request['config'].get('apikey'): misperrors['error'] = 'A VirusTotal api key is required for this module.' return misperrors 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.'} event_limit = request['config'].get('event_limit') attribute = request['attribute'] proxy_settings = get_proxy_settings(request.get('config')) try: client = vt.Client(request['config']['apikey'], headers={ 'x-tool': 'MISPModuleVirusTotalPublicExpansion', }, proxy=proxy_settings['http'] if proxy_settings else None) parser = VirusTotalParser(client, int(event_limit) if event_limit else None) parser.query_api(attribute) except vt.APIError as ex: misperrors['error'] = ex.message return misperrors return parser.get_result() def introspection(): return mispattributes def version(): moduleinfo['config'] = moduleconfig return moduleinfo