MozDef/alerts/multiple_intel_hits.py

64 строки
3.0 KiB
Python

#!/usr/bin/env python
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at https://mozilla.org/MPL/2.0/.
# Copyright (c) 2014 Mozilla Corporation
from lib.alerttask import AlertTask
from mozdef_util.query_models import SearchQuery, TermMatch, ExistsMatch, TermsMatch
class AlertMultipleIntelHits(AlertTask):
def main(self):
search_query = SearchQuery(minutes=2)
search_query.add_must([
TermMatch('category', 'bro'),
TermMatch('source', 'intel'),
ExistsMatch('details.seenindicator'),
TermsMatch('hostname', ['sensor1', 'sensor2', 'sensor3'])
])
self.filtersManual(search_query)
# Search aggregations on field 'seenindicator', keep X samples of events at most
self.searchEventsAggregated('details.seenindicator', samplesLimit=10)
# alert when >= X matching events in an aggregation
self.walkAggregations(threshold=10)
# Set alert properties
def onAggregation(self, aggreg):
# aggreg['count']: number of items in the aggregation, ex: number of failed login attempts
# aggreg['value']: value of the aggregation field, ex: toto@example.com
# aggreg['events']: list of events in the aggregation
category = 'bro'
tags = ['nsm,bro,intel']
severity = 'NOTICE'
hostname = aggreg['events'][0]['_source']['hostname']
summary = '{0} {1} {2} on {3}'.format(aggreg['count'], hostname, ' Bro intel match for indicator:', aggreg['value'])
summary += ' sample hosts that hit it: '
for e in aggreg['events'][:3]:
if 'details' in e['_source'] \
and 'sourceipaddress' in e['_source']['details'] \
and 'seenwhere' in e['_source']['details']:
interestingaddres = ''
# someone talking to a bad guy, I want to know who
# someone resolving bad guy's domain name, I want to know who
# bad guy talking to someone, I want to know to whom
if ('Conn::IN_RESP' in e['_source']['details']['seenwhere'] or
'HTTP::IN_HOST_HEADER' in e['_source']['details']['seenwhere'] or
'DNS::IN_REQUEST' in e['_source']['details']['seenwhere']):
interestingaddres = e['_source']['details']['sourceipaddress']
elif ('Conn::IN_ORIG' in e['_source']['details']['seenwhere'] or
'HTTP::IN_X_CLUSTER_CLIENT_IP_HEADER' in e['_source']['details']['seenwhere'] or
'HTTP::IN_X_FORWARDED_FOR_HEADER' in e['_source']['details']['seenwhere']):
interestingaddres = e['_source']['details']['destinationipaddress']
summary += '{0} in {1} '.format(interestingaddres, e['_source']['details']['seenwhere'])
# Create the alert object based on these properties
return self.createAlertDict(summary, category, tags, aggreg['events'], severity)