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