CSO from CiBMall has no longer operation, and will no able to play anymore.
Here is Announcement from official CiBMall
Notice for CSO Game Closure
Dear players,
It’s been (8) years since the game first launched and we’ve shared a lot of great moments with our players in game. We would like to take this opportunity to sincerely thank all players whom have supported CSO all these while and we regretfully announce that CSO will stop all operations starting (30/9/2014). The servers will shut down on the mentioned date and players will no longer be able to login to the game starting (30/9/2014).