MozDef/alerts/ssh_access_signreleng.py

75 строки
2.5 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) 2017 Mozilla Corporation
#
# Contributors:
# Aaron Meihm <ameihm@mozilla.com>
# Brandon Myers bmyers@mozilla.com
from lib.alerttask import AlertTask
from query_models import SearchQuery, TermMatch, PhraseMatch, QueryStringMatch
import re
import json
class AlertAuthSignRelengSSH(AlertTask):
def main(self):
search_query = SearchQuery(minutes=15)
self.parse_config('ssh_access_signreleng.conf', ['hostfilter', 'ircchannel', 'exclusions'])
if self.config.ircchannel == '':
self.config.ircchannel = None
exclusions = json.loads(self.config.exclusions)
search_query.add_must([
TermMatch('tags', 'releng'),
TermMatch('details.program', 'sshd'),
QueryStringMatch('details.hostname: /{}/'.format(self.config.hostfilter)),
PhraseMatch('summary', 'Accepted publickey for ')
])
for exclusion in exclusions:
exclusion_query = None
for key, value in exclusion.iteritems():
phrase_exclusion = PhraseMatch(key, value)
if exclusion_query is None:
exclusion_query = phrase_exclusion
else:
exclusion_query = exclusion_query + phrase_exclusion
search_query.add_must_not(exclusion_query)
self.filtersManual(search_query)
self.searchEventsSimple()
self.walkEvents()
# Set alert properties
def onEvent(self, event):
category = 'access'
tags = ['ssh']
severity = 'NOTICE'
targethost = 'unknown'
sourceipaddress = 'unknown'
x = event['_source']
if 'details' in x:
if 'hostname' in x['details']:
targethost = x['details']['hostname']
if 'sourceipaddress' in x['details']:
sourceipaddress = x['details']['sourceipaddress']
targetuser = 'unknown'
expr = re.compile('Accepted publickey for ([A-Za-z0-9]+) from')
m = expr.match(event['_source']['summary'])
groups = m.groups()
if len(groups) > 0:
targetuser = groups[0]
summary = 'SSH login from {0} on {1} as user {2}'.format(sourceipaddress, targethost, targetuser)
return self.createAlertDict(summary, category, tags, [event], severity, ircchannel=self.config.ircchannel)