/usr/share/php/Symfony/Component/Security/Core/Encoder/ is in php-symfony-security 2.7.10-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Symfony/Component/Security/Core/Encoder/BCryptPasswordEncoder.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/BasePasswordEncoder.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/EncoderAwareInterface.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/EncoderFactory.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/EncoderFactoryInterface.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/MessageDigestPasswordEncoder.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/PasswordEncoderInterface.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/Pbkdf2PasswordEncoder.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/PlaintextPasswordEncoder.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/UserPasswordEncoder.php
/usr/share/php/Symfony/Component/Security/Core/Encoder/UserPasswordEncoderInterface.php