This is Shutter upload plugin for Yandex.Disk service. For Shutter, see http://shutter-project.org and it is probably available in your distro package repository.
Installing Shutter is easy in Ubuntu:
$ sudo apt-get install shutter
This plugin requires HTTP::DAV Perl module from CPAN. To install either use CPAN:
$ sudo cpan install HTTP::DAV
or your package repository:
$ sudo apt-get install libhttp-dav-perl
Then put the file YandexDisk.pm into /usr/share/shutter/resources/system/upload_plugins/upload/ directory.
Now you need to run Shutter and configure your Yandex login and password in the Preferences dialog, page Upload.
Then it will show up in your Upload dialog along with all other services that Shutter supports.
No OAuth support.