Guild Wars 2 is barely a week old, but the new massively multiplayer online role-playing game has already suffered a significant security breach.

Hackers have obtained more than 11,000 player passwords, reports ArsTechnica. They’ve done this by breaching an unnamed fan site and then checking if the credentials players used there were identical to corresponding logins for Guild Wars 2 accounts.

“Over the past three days, we’ve received approximately 8,500 new support tickets related to hacked accounts and other blocking login issues, and we’ve resolved issues to get approximately 9,500 players back into the game (most from tickets submitted prior to Friday, August 31),” said staff from developer ArenaNet the Guild Wars 2’s wiki. “We’re aggressively ramping up our customer support team, with 28 new support representatives starting today and more coming online in the next few days, to provide the fast response times our customers expect.”

ArenaNet is prioritizing all customer tickets related to hacked accounts submitted before August 31. The developer also urges players to protect themselves by using strong, long, unique passwords.

Players have to confirm login locations via e-mail. For example, if someone from China had my password and tried to play as one of my characters, I would receive a notification from ArenaNet asking me to authorize use of my account from that area. This keeps them from playing my Guild Wars 2 profile, but they still have my password, which is especially dangerous if I use it for multiple logins.

If you notice anything weird about your Guild Wars 2 account or receive an e-mail stating that someone accessed your characters from a strange location, you should contact ArenaNet immediately. Regardless, it’s a good idea for everyone to change their passwords. Now, excuse me while I do exactly that.