MozDef/alerts/write_audit.py

45 строки
1.7 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
#
# This code alerts on every successfully opened session on any of the host from a given list
from lib.alerttask import AlertTask
from mozdef_util.query_models import SearchQuery, TermMatch, QueryStringMatch, PhraseMatch
class WriteAudit(AlertTask):
def main(self):
self.parse_config('write_audit.conf', ['skipprocess'])
search_query = SearchQuery(minutes=15)
search_query.add_must([
TermMatch('category', 'write'),
TermMatch('details.auditkey', 'audit'),
])
for processname in self.config.skipprocess.split():
search_query.add_must_not(PhraseMatch('details.processname', processname))
self.filtersManual(search_query)
self.searchEventsAggregated('details.originaluser', samplesLimit=10)
self.walkAggregations(threshold=2)
def onAggregation(self, aggreg):
category = 'write'
severity = 'WARNING'
tags = ['audit']
summary = ('{0} Filesystem write(s) to an auditd path by {1}'.format(aggreg['count'], aggreg['value'], ))
hostnames = self.mostCommon(aggreg['allevents'],'_source.hostname')
#did they modify more than one host?
#or just modify an existing configuration more than once?
if len(hostnames) > 1:
for i in hostnames[:5]:
summary += ' on {0} ({1} hosts)'.format(i[0], i[1])
return self.createAlertDict(summary, category, tags, aggreg['events'], severity)