MozDef/alerts/proxy_drop_non_standard_por...

59 строки
2.1 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 http://mozilla.org/MPL/2.0/.
# Copyright (c) 2014 Mozilla Corporation
from lib.alerttask import AlertTask
from mozdef_util.query_models import QueryStringMatch, SearchQuery, TermMatch
class AlertProxyDropNonStandardPort(AlertTask):
def main(self):
self.parse_config(
'proxy_drop_non_standard_port.conf', ['excludedports'])
search_query = SearchQuery(minutes=20)
search_query.add_must([
TermMatch('category', 'squid'),
TermMatch('tags', 'squid'),
TermMatch('details.proxyaction', 'TCP_DENIED/-'),
TermMatch('details.tcpaction', 'CONNECT')
])
# Only notify on certain ports from config
port_regex = "/.*:({0})/".format(
self.config.excludedports.replace(',', '|'))
search_query.add_must_not([
QueryStringMatch('details.destination: {}'.format(port_regex))
])
self.filtersManual(search_query)
# Search aggregations on field 'hostname', keep X samples of
# events at most
self.searchEventsAggregated('details.sourceipaddress', samplesLimit=10)
# alert when >= X matching events in an aggregation
# I think it makes sense to alert every time here
self.walkAggregations(threshold=1)
def onAggregation(self, aggreg):
category = 'squid'
tags = ['squid', 'proxy']
severity = 'WARNING'
destinations = set()
for event in aggreg['allevents']:
destinations.add(event['_source']['details']['destination'])
summary = 'Suspicious Proxy DROP event(s) detected from {0} to the following non-std port destination(s): {1}'.format(
aggreg['value'],
",".join(sorted(destinations))
)
# Create the alert object based on these properties
return self.createAlertDict(summary, category, tags, aggreg['events'], severity)