1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
<?php
/**
* @copyright Copyright (c) 2018 Matthias Held <matthias.held@uni-konstanz.de>
* @author Matthias Held <matthias.held@uni-konstanz.de>
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
namespace OCA\RansomwareDetection\Connector\Sabre;
use OCA\RansomwareDetection\Classifier;
use OCA\RansomwareDetection\AppInfo\Application;
use OCA\RansomwareDetection\Analyzer\SequenceAnalyzer;
use OCA\RansomwareDetection\Service\FileOperationService;
use OCP\Notification\IManager;
use OCP\IUserSession;
use OCP\ISession;
use OCP\ILogger;
use OCP\IConfig;
use Sabre\DAV\Server;
use Sabre\DAV\ServerPlugin;
use Sabre\HTTP\RequestInterface;
use Sabre\HTTP\ResponseInterface;
class RequestPlugin extends ServerPlugin
{
/** @var Server */
protected $server;
/** @var ILogger */
protected $logger;
/** @var IConfig */
protected $config;
/** @var IUserSession */
protected $userSession;
/** @var ISession */
protected $session;
/** @var FileOperationService */
protected $service;
/** @var IManager */
protected $notifications;
/** @var Classifier */
protected $classifier;
/** @var SequenceAnalyzer */
protected $sequenceAnalyzer;
const PROPFIND_COUNT = 6;
/**
* @param ILogger $logger
* @param IConfig $config
* @param IUserSession $userSession
* @param ISession $session
* @param FileOperationService $service
* @param IManager $notifications
* @param Classifier $classifer
* @param SequenceAnalyzer $sequenceAnalyzer
*/
public function __construct(
ILogger $logger,
IConfig $config,
IUserSession $userSession,
ISession $session,
FileOperationService $service,
IManager $notifications,
Classifier $classifier,
SequenceAnalyzer $sequenceAnalyzer
) {
$this->logger = $logger;
$this->config = $config;
$this->userSession = $userSession;
$this->session = $session;
$this->service = $service;
$this->notifications = $notifications;
$this->classifier = $classifier;
$this->sequenceAnalyzer = $sequenceAnalyzer;
}
public function initialize(Server $server)
{
$this->server = $server;
$server->on('method:PROPFIND', [$this, 'beforeHttpPropFind'], 100);
$server->on('method:PUT', [$this, 'beforeHttpPut'], 100);
$server->on('method:DELETE', [$this, 'beforeHttpDelete'], 100);
$server->on('method:GET', [$this, 'beforeHttpGet'], 100);
$server->on('method:POST', [$this, 'beforeHttpPost'], 100);
}
public function beforeHttpPropFind(RequestInterface $request, ResponseInterface $response)
{
$propfindCount = $this->config->getUserValue($this->userSession->getUser()->getUID(), Application::APP_ID, 'propfind_count:'.$this->session->getId(), 0);
if ($propfindCount + 1 < self::PROPFIND_COUNT) {
// less than PROPFIND_COUNT + 1 PROPFIND requests
$this->config->setUserValue($this->userSession->getUser()->getUID(), Application::APP_ID, 'propfind_count:'.$this->session->getId(), $propfindCount + 1);
} else {
// more than PROPFIND_COUNT PROPFIND requests and no file is uploading
$sequenceId = $this->config->getUserValue($this->userSession->getUser()->getUID(), Application::APP_ID, 'sequence_id', 0);
$sequence = $this->service->findSequenceById([$sequenceId]);
if (sizeof($sequence) > 0) {
// get old sequence id
// start a new sequence by increasing the sequence id
$this->config->setUserValue($this->userSession->getUser()->getUID(), Application::APP_ID, 'sequence_id', $sequenceId + 1);
$this->config->setUserValue($this->userSession->getUser()->getUID(), Application::APP_ID, 'propfind_count:'.$this->session->getId(), 0);
$this->classifySequence($sequence);
}
}
}
public function beforeHttpPut(RequestInterface $request, ResponseInterface $response)
{
// extend if necessary
}
public function beforeHttpDelete(RequestInterface $request, ResponseInterface $response)
{
// extend if necessary
}
public function beforeHttpGet(RequestInterface $request, ResponseInterface $response)
{
// extend if necessary
}
public function beforeHttpPost(RequestInterface $request, ResponseInterface $response)
{
// extend if necessary
}
/**
* Triggers a notification.
*/
private function triggerNotification($notification)
{
$notification->setApp(Application::APP_ID);
$notification->setDateTime(new \DateTime());
$notification->setObject('ransomware', 'ransomware');
$notification->setSubject('ransomware_attack_detected', []);
$notification->setUser($this->userSession->getUser()->getUID());
$this->notifications->notify($notification);
}
/**
* Classify sequence and if suspicion level is reached
* trigger a notification.
*
* @param array $sequence
*/
private function classifySequence($sequence)
{
$sequenceSuspicionLevel = $this->config->getAppValue(Application::APP_ID, 'suspicion_level', 2);
foreach ($sequence as $file) {
$this->classifier->classifyFile($file);
}
// sequence suspicion level
if ($sequenceSuspicionLevel === 1) {
$level = 2;
} else {
$level = 4;
}
// sequence id is irrelevant so we use 0
$sequenceResult = $this->sequenceAnalyzer->analyze(0, $sequence);
if ($sequenceResult->getSuspicionScore() >= $level) {
$this->triggerNotification($this->notifications->createNotification());
}
}
}
|
