Step 2: Secure Your E-mail Account
After you have secured your computer, please create a new password for your e-mail account since it may also be compromised. Be sure to check your e-mail filters and rules and look for any e-mail forwarding rules that you did not create. For more information on securing your e-mail account, visit this Support page
Step 3: Choose a New Password
You must change your password in order to resume using this Battle.net account. Check your email for further instructions or visit http://us.battle.net/account/support/password-reset.html to initiate a new password reset e-mail.
Note that your former password no longer grants access to Battle.net account management, World of Warcraft, or any other login-protected Battle.net account service.
If you still have questions or concerns after following the steps above, feel free to contact Customer Support at http://us.blizzard.com/support/article.xml?locale=en_US&articleId=20606.