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<?php |
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/** |
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* @copyright Copyright (c) 2017 Matthias Held <[email protected]> |
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* @author Matthias Held <[email protected]> |
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* @license GNU AGPL version 3 or any later version |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU Affero General Public License as |
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* published by the Free Software Foundation, either version 3 of the |
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* License, or (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Affero General Public License for more details. |
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* |
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* You should have received a copy of the GNU Affero General Public License |
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* along with this program. If not, see <https://www.gnu.org/licenses/>. |
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*/ |
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namespace OCA\RansomwareDetection\Analyzer; |
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use OCA\RansomwareDetection\AppInfo\Application; |
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use OCA\RansomwareDetection\FileSignatures; |
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use OCP\Files\IRootFolder; |
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use OCP\Files\NotFoundException; |
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use OCP\Files\File; |
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use OCP\ILogger; |
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class FileCorruptionAnalyzer |
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{ |
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/** @var ILogger */ |
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private $logger; |
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/** @var IRootFolder */ |
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private $rootFolder; |
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/** @var string */ |
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private $userId; |
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/** |
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* @param ILogger $logger |
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* @param IRootFolder $rootFolder |
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* @param string $userId |
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*/ |
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public function __construct( |
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ILogger $logger, |
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IRootFolder $rootFolder, |
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$userId |
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) { |
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$this->logger = $logger; |
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$this->rootFolder = $rootFolder; |
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$this->userId = $userId; |
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} |
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/** |
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* Analysis a file if it's corrupted or not. |
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* |
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* @param File $node |
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* @return FileCorruptionResult |
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*/ |
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public function analyze($node) |
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{ |
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return $this->isCorrupted($node); |
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} |
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/** |
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* Checks the file for existing file header informations and compares them, |
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* if found, to the file extension. |
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* |
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* @param File $node |
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* @return FileCorruptionResult |
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*/ |
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protected function isCorrupted(File $node) |
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{ |
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$signatures = FileSignatures::getSignatures(); |
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try { |
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// get the first 1024 bytes |
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$handle = $node->fopen('r'); |
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$data = fread($handle, 1024); |
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fclose($handle); |
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$pathInfo = pathinfo($node->getPath()); |
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foreach ($signatures as $signature) { |
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$isFileCorrupted = true; |
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if (isset($pathInfo['extension']) && in_array(strtolower($pathInfo['extension']), $signature['extensions'])) { |
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// txt file extension has no signature, but is not corrupted |
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if (array_key_exists('exists', $signature['signature'])) { |
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if ($signature['signature']['exists'] === false) { |
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return new FileCorruptionResult(false); |
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} |
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} |
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// starting byte sequence |
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if (array_key_exists('starting', $signature['signature'])) { |
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foreach ($signature['signature']['starting']['bytes'] as $bytes) { |
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if (preg_match($bytes, strtolower(bin2hex(substr($data, $signature['signature']['starting']['offset'], strlen($bytes) / 2))))) { |
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$isFileCorrupted = false; |
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} |
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} |
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} |
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// trailing byte sequence |
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if (array_key_exists('trailing', $signature['signature'])) { |
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$trailingIsNotMatching = true; |
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foreach ($signature['signature']['trailing']['bytes'] as $bytes) { |
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$trailingOffset = strlen($data) - $signature['signature']['trailing']['offset'] - strlen($bytes) / 2; |
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if (preg_match($bytes, strtolower(bin2hex(substr($data, $trailingOffset, strlen($bytes) / 2))))) { |
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$trailingIsNotMatching = false; |
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} |
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} |
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$isFileCorrupted = $isFileCorrupted || $trailingIsNotMatching; |
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return new FileCorruptionResult($isFileCorrupted); |
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} |
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return new FileCorruptionResult($isFileCorrupted); |
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} |
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} |
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return new FileCorruptionResult(false); |
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} catch (\OCP\Files\NotPermittedException $exception) { |
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$this->logger->debug('isCorrupted: Not permitted.', array('app' => Application::APP_ID)); |
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return new FileCorruptionResult(false); |
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} catch (\OCP\Lock\LockedException $exception) { |
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$this->logger->debug('isCorrupted: File is locked.', array('app' => Application::APP_ID)); |
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return new FileCorruptionResult(false); |
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} |
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} |
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} |
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undo-ransomware /
ransomware_detection
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The issue could also be caused by a filter entry in the build configuration. If the path has been excluded in your configuration, e.g.
excluded_paths: ["lib/*"], you can move it to the dependency path list as follows:For further information see https://scrutinizer-ci.com/docs/tools/php/php-scrutinizer/#list-dependency-paths